Answer:
(i) 32.9 mL; (ii) 37.5 mL; (iii) 21.73 mL
Explanation:
You should always try to read a measuring instrument to a tenth of the smallest scale division.
Here, you are measuring liquids, so you take the scale reading from the bottom of the meniscus.
(i) Graduated cylinder
There are 10 divisions between 30 mL and 40 mL, so each division represents 1 mL.
The level of the liquid appears to be between 32 mL and 33 mL. It is much closer to 33 mL (perhaps right on 33 mL).
You should report the volume to the nearest 0.1 mL. I would read the volume as 32.9 mL, but 32.8 and 33.0 are also acceptable.
Note: If you think the level is right on the 33 mark, you report the volume as 33.0 mL (NOT 33 mL).
(ii) Thermometer
The reading is about half-way between 87 ° and 88 °.
I would report the temperature as 87.5 °, but 87.4 ° and 87.6 ° would also be acceptable.
(iii) Buret
There are 10 divisions between 21 mL and 22 mL, so each division represents 0.1 mL.
You should estimate to the nearest 0.01 mL.
The liquid level is about a third of the way from 21.7 mL to 21.8 mL.
I would report the volume as 21.73 mL, but 21.72 mL and 21.74 mL are also acceptable.
How many grams of O are in 675 g of Na2O
42 mole Al= how many atoms?
2.5 × 10²³ atoms Al
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
42 mol Al
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
Set up: \(\displaystyle 42 \ mol \ Al(\frac{6.022 \cdot 10^{23} \ atoms \ Al}{1 \ mol \ Al})\)Multiply/Divide: \(\displaystyle 2.52924 \cdot 10^{25} \ atoms \ Al\)Step 4: Check
Follow sig fig rules and round. We are given 2 sig figs.
2.52924 × 10²³ atoms Al ≈ 2.5 × 10²³ atoms Al
What is the chemical formula for iron(11) oxide
Answer:
FeO
Explanation:
Iron(II) oxide or ferrous oxide is the inorganic compound with the formula FeO. Its mineral form is known as wüstite. One of several iron oxides, it is a black-colored powder that is sometimes confused with rust, the latter of which consists of hydrated iron(III) oxide (ferric oxide).
How do the valence electrons of an atom affect chemical reactions?
Valence electrons are the electrons in the outermost shell of an atom and are responsible for chemical reactions. In a chemical reaction, atoms gain or lose electrons to achieve a stable electron configuration, which is known as the octet rule. The number of valence electrons an atom has determines its chemical reactivity and how it will bond with other atoms. For example, atoms with only a few valence electrons, such as hydrogen, are highly reactive and will readily form chemical bonds, while atoms with many valence electrons, such as noble gases, are relatively unreactive and do not easily form chemical bonds.
Which refers to the passing of a wave through an object?
sound
O interference
O transmission
O frequency
O sound
The term that refers to the passing of a wave through an object is "transmission."
Transmission refers to the process by which a wave passes through an object or medium. In the context of sound, transmission occurs when sound waves travel through different substances, such as air, water, or solids.
When a sound wave encounters an object, it can be transmitted through it, reflected off it, or absorbed by it, depending on the properties of the object and the medium through which the sound is traveling.
For example, when you speak into a microphone, the sound waves produced by your voice travel through the air and are transmitted to the microphone's diaphragm. The diaphragm converts the sound waves into electrical signals, which can then be amplified and reproduced as sound through speakers.
In summary, transmission is the term used to describe the passage of a wave, such as a sound wave, through an object or medium. It is an essential concept in understanding how waves interact with their surroundings and how sound propagates through different materials.
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1. Which solvent is best for the following solute. Explain why
a.
Explain:
a
9:0:
A
CH₂
H₂c
H₂c
b
HC
HC.
CH₂
CH
CH₂
CH₂
HC-0:
The solubility of the solute in the solvent depends on intermolecular interactions.
How does the nature of the solvent affect its ability to dissolve a solute?The nature of the solute and the solvent alone determines how soluble they are in a solvent. In a polar solvent, a polar solute dissolves. In a non-polar solvent, a polar solute is poorly soluble. In a non-polar solvent, a non-polar solute dissolves.
Since the question is incomplete, we can not see what the solute or the solvent ought to have been. However, we must know that the solubility of the solute in the solvent must depend on intermolecular interactions between the both.
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18.07 Lab Acid Neutralization 1
Carry out the following conversions. Report your answers to the correct number of significant
figures.
(a) 75 cm to ft
ft
(b) 0.668 kg to lb
Ib
(e) 0.549 uL to qt
* 10-qt
(d) 9,991 mm to km
9.991 x 10 (select)
km
(e) 313 nm to mm
3.13 x 10 (select)
mm
(1) 7 ft to cm
* 102 cm
We want to perform some changes of units, such that the number of significant figures (the ones different than zero) does not change.
a) 75 cm to ft
We know that:
1ft = 30.48cm
1 = (1ft)/(30.48cm)
Now, remember that if we multiply a quantity by one we do not affect the quantity, so we can write:
75cm = 75cm*(1ft)/(30.48cm) = 2.5 ft
b) 0.668 kg to lb
we know that:
1kg = 2.20462 lb
then:
1 = (2.20462 lb)/(1kg)
0.668 kg = 0.668 kg*(2.20462 lb)/(1kg) = 1.47 lb
c) 0.549 uL to qt
We know that:
1 uL = 3.437*10^-9 qt
1 = (3.437*10^-9 qt)/(1 uL)
Then:
0.549 uL = 0.549 uL*(3.437*10^-9 qt)/(1 uL) = 1.91*10^-9 qt
d) 9.991 mm to km
we know that:
1mm = 1*10^-6 km
then:
1 = (1*10^-6 km)/(1mm)
So we can rewrite:
9.991 mm = 9.991 mm*(1*10^-6 km)/(1mm) = 9.991*10^-6 km
e) 313 nm to mm
We have:
1nm = 1*10^-6 mm
1 = ( 1*10^-6 mm)/(1 nm)
Then:
313 nm*( 1*10^-6 mm)/(1 nm) = 3.13*10^-4 mm
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what is the number of electron layers of a iron atom that is in ground state?
A) 5
B) 7
C) 4
D) 52
The number of energy levels in iron atom in its ground state is 4. The valence electrons in iron fills in 4s and 3d orbitals.
What is iron ?Iron is 26th element in periodic table. It is located in d-block and is called a transition metal. Like all other transition metals, Fe also exhibit the variable oxidation states.
The electrons in an atom fills in different energy levels from lower energy level to the higher energy level. Fe contains total 26 electrons out of which 8 are valence electrons.
Among this 8 electrons, 2 are in 4s orbital and 6 are in 3d orbital. The largest occupied energy level is n =4. Therefore, the number of shell in Fe is 4.
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What are the complete Ionic and Net Ionic equations for the following
a) CaCl2(aq) + Pb(NO3)2(aq) → PbCl2(s) + Ca(NO3)2(aq)
b) CaCl2(aq) + Na2CO3(aq) → CaCO3(s) + 2NaCl2(aq)
c) 2AgNO3 (aq) + BaI2(aq) → Ba(NO3)2 (aq) + 2AgI (s)
Answer:
Check photo
Explanation:
I NEED HELP ASAP!!!
Which answer below correctly identifies the type of change and the explanation when potassium iodide and lead nitrate are mixed?
physical change because the observation of a solid forming is evidence of a state change, which is reversible
physical change because even though the mixture had a color that was different from either of the two solids alone, each solid's physical properties remained exactly the same
chemical change because two substances were mixed, which always results in the formation of a
new substance
chemical change because both a color change and a solid formation were observed, which provide strong evidence of a new substance
Answer:
The correct answer is chemical change because both a color change and a solid formation were observed, which provide strong evidence of a new substance.
A physical change is a change in the state of a substance, such as a change from a solid to a liquid or a change from a liquid to a gas. A chemical change is a change in the composition of a substance, such as the formation of a new substance.
When potassium iodide and lead nitrate are mixed, a yellow precipitate forms. This precipitate is a new substance that was not present before the two substances were mixed. Therefore, the change that occurs when potassium iodide and lead nitrate are mixed is a chemical change.
The other answers are incorrect.
* Answer 1 is incorrect because the observation of a solid forming is not evidence of a state change. A state change is a change in the physical state of a substance, such as a change from a solid to a liquid or a change from a liquid to a gas. The formation of a precipitate is not a state change, but rather a chemical change.
* Answer 2 is incorrect because the color change of the mixture is evidence of a chemical change. When two substances are mixed and a new substance is formed, the new substance may have a different color than the original substances.
* Answer 3 is incorrect because the statement "two substances were mixed, which always results in the formation of a new substance" is not always true. For example, if you mix two different types of liquids, you may not get a new substance. Instead, you may just get a mixture of the two liquids.
The reaction between potassium iodide and lead nitrate results in a chemical change because a color change and solid formation, indicative of a new substance, are observed.
Explanation:When potassium iodide and lead nitrate are mixed, there is a chemical change that takes place. This is because both a color change and a solid formation were observed, which provide strong evidence of a new substance. In this reaction, two new compounds are formed - lead iodide and potassium nitrate - which is a clear indication of a chemical change. This process is not easily reversible, further supporting it being a chemical change.
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B. For items 6-10, identify at least one element present in each of the following
food products:
8.
7.
6.
9.
10.
Which set of elements have the most similar chemical properties?
Potassium, Calcium, Scandium
Chromium, Cobalt, Copper
Oxygen, Sulfur, Selenium
Nitrogen, Oxygen, Fluorine
answer: A not sure but i hope it helps :) success
Ca(s) + 2H₂O(l) → Ca(OH)₂(aq) + H₂(g) 14. Calcium reacts with water according to the above reaction. What volume of hydrogen gas, at standard temperature and pressure, is produced from 0.200 moles of calcium?
According to the stoichiometry, 0.4 ml of hydrogen gas is produced from 0.2 moles of calcium .
What is stoichiometry?It is the determination of proportions of elements or compounds in a chemical reaction. The related relations are based on law of conservation of mass and law of combining weights and volumes.
Stoichiometry is used in quantitative analysis for measuring concentrations of substances present in the sample.
In the given problem, 1 mole of calcium produces 1 mole of hydrogen gas.
Given 0.2 moles of calcium , so mass of calcium by number of moles formula,mass=number of moles×molar mass=0.2×40.07=8.014 g
As 40.07 g of calcium produces 2 g hydrogen
∴8.014 g calcium produces 8.014×2/40.07=0.4 ml.
Thus, the volume of hydrogen gas produced from 0.2 moles of calcium at standard temperature and pressure is 0.4 ml.
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How many grams of sodium (Na) are in 6.2 mol of Na?
mass = mol no. x molar mass
= 6.2 x 23
= 142.6 g
Removing the tip of the stem in a young plant will most directly interfere with the production of
a. auxins b. carbon dioxide c. oxygen d. neurotransmitters
Answer:
c.
Explanation:
c) Discuss precision and Accuracy as they relate to types of errors.
what is the answer
Precision relates to the consistency and reproducibility of measurements, while accuracy reflects how close measurements are to the true value.
Precision and accuracy are two important concepts in the context of errors in measurements. While they both pertain to the quality of data, they refer to different aspects.
Precision refers to the degree of consistency or reproducibility in a series of measurements. It reflects the scatter or spread of data points around the average value. If the measurements have low scatter and are tightly clustered, they are considered precise. On the other hand, if the measurements have a high scatter and are widely dispersed, they are considered imprecise.
Accuracy, on the other hand, refers to the closeness of measurements to the true or target value. It represents how well the measured values align with the actual value. Accuracy is achieved when measurements have a small systematic or constant error, which is the difference between the average measured value and the true value.
Errors in measurements can be classified into two types: random errors and systematic errors.
Random errors are associated with the inherent limitations of measurement instruments or fluctuations in the measurement process. They lead to imprecise data and affect the precision of measurements. Random errors can be reduced by repeating measurements and calculating the average to minimize the effect of individual errors.
Systematic errors, on the other hand, are caused by consistent biases or inaccuracies in the measurement process. They affect the accuracy of measurements and lead to a deviation from the true value. Systematic errors can arise from factors such as instrumental calibration issues, environmental conditions, or experimental techniques. These errors need to be identified and minimized to improve the accuracy of measurements.
In summary, precision refers to the degree of consistency or reproducibility of measurements, while accuracy refers to the closeness of measurements to the true value. Random errors affect precision, while systematic errors affect accuracy. To ensure high-quality measurements, both precision and accuracy need to be considered and appropriate techniques should be employed to minimize errors.
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Can we solve this using factor label?
\(0.0169 \ gal = 64 \ cm^{3}\)
\(1 \ gal = 3.785412 * 10^{-3} \ m^{3}\)
\(1 \ cm^{3} = 1 * 10^{-6} \ m^{3}\)
Use the process of photosynthesis and cellular respiration to describe why the drought has driven the bears into the towns.
The process of photosynthesis and cellular respiration is usually at the barest minimum when drought occurs.
What is Photosynthesis?This is the process in which green plants manufacture their food through the presence of light energy from the Sun.
During drought, there is no water which reduces photosynthetic activity of plants. This leads to shortage of food thereby making bears to come into town in search of food.
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Gas Laws
Pre-Test Active
1
2 3
5
6
O final pressure
O atmospheric pressure
O combined pressure
O partial pressure
7 8
9
10
A scientist is measuring the pressure that is exerted by each of the following gases in the atmosphere: carbon dioxide,
oxygen, and nitrogen. Which term most likely describes what she is measuring?
The term that the scientist would use in this case is partial pressure. Option D
What is the partial pressure?
The pressure that one particular gas component within a mixture of gases exerts is referred to as partial pressure. It is the pressure that the gas would experience at the same temperature if it were the only thing in the entire volume.
When researching gas mixtures, such as in gas laws, gas phase equilibria, and gas collecting methods, partial pressures are extremely crucial for the gas.
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Write the equation for the equilibrium constant (K) of the reaction studied in this exercise.
2C04 2- (ag) + 2Ht (ag) = CI20, 2- (ag) + H20(1)
The equation for the equilibrium constant (K) of the reaction studied in this exercise can be written as follows: K = ([\(CI_20\), 2-] * [\(H_20\)(1)]) / ([\(C0_4^ 2\)-] * [Ht])
In this equation, the concentrations of the species involved in the reaction are represented by the square brackets [ ]. The subscripts indicate the stoichiometric coefficients of each species in the balanced chemical equation.
The reaction being studied involves the following species:
\(C0_4^ 2\)- (ag) + 2Ht (ag) = \(CI_20\), 2- (ag) + \(H_20\)(1)
In the equilibrium constant expression, the concentration of \(CI_20\), 2- is multiplied by the concentration of \(H_20\)(1) and divided by the product of the concentrations of \(C0_4^ 2\)- and Ht. The stoichiometric coefficients in the balanced equation are used as exponents for the concentrations of the respective species.
It is important to note that the concentrations used in the equilibrium constant expression should be in molar units (mol/L) or expressed as partial pressures for gases.
Additionally, the equilibrium constant is specific to a given temperature, and its value provides information about the relative amounts of reactants and products at equilibrium.
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what three forces are in tug of war?
The element silver has an atomic weight of 108 and consists of two stable isotopes silver-107 and silver-109. The isotope silver-107 has a mass of 107 amu and a percent natural abundance of 51.8 %. The isotope silver-109 has a percent natural abundance of 48.2 %. What is the mass of silver-109
Answer:
109
Explanation:
Let silver-107 be isotope A
Let silver-109 be isotope B
Let silver-107 abundance be A%
Let silver-109 abundance be B%
The following data were obtained from the question:
Atomic weight of silver = 108
Mass of isotope A (silver-107) = 107
Abundance of isotope A (silver-107) = 51.8%
Abundance of isotope B (silver-109) = 48.2%
Mass of isotope B (silver-109) =?
Now, we shall determine the mass silver-109 as follow:
Atomic weight = [(Mass of A x A%)/100] + [(Mass of B x B%)/100]
108 = [(107 x 51.8)/100] + [(Mass of B x 48.2)/100]
108 = 55.426 + (Mass of B x 0.482)
Collect like terms
Mass of B x 0.482 = 108 – 55.426
Mass of B x 0.482 = 52.574
Divide both side by 0.482
Mass of B = 52.574/0.482
Mass of B = 109
Therefore, the mass of silver-109 is 109.
In which of the following, are all the elements non-metals?
A. Na, Mg, O, N
B. C, Si, Ge, As
C. Fe, Ni, Cr, O
D. He, Ne, Ar, Kr
E. Ca, Ba, Sr, S
Answer:
The answer is D
Explanation:
Non metals are:
Hydrogen (H)
Sulphur (S)
Phosphorus (P)
Carbon (C)
Fluorine (F)
Oxygen (O)
Nitrogen (N)
Chlorine (Cl)
Bromine (Br)
Helium (He)
Argon (Ar)
Iodine (I)
Neon (Ne)
Krypton (Kr)
Radon (Rn)
Selenium (Se)
Xenon (Xe)
Which two nuclides are isotopes of the same element
Answer:
1940K and 1939K Isotopes are two forms of the same element that have different numbers of neutrons in the nucleus. This means same symbol, and same atomic number (subscript), but different mass number (superscript).
For each of the substances below, label them as acids (A), bases (B), or neutral (N), then place them where they best belong on the pH scale. You may need to research some substances' pH if you are not familiar with them.
__ baking soda
__ Vinegar
__ Distilled water
__ “Pure” rain
__ Ammonia
__ Lemon juice
__ Hair and skin
To research some substances pH 0 to less than 7 is acidic, 7 is neutral and more than 7 is neutral.
baking soda - base
Vinegar - acid
Distilled water - neutral
Pure rain - neutral
Ammonia - nasic
Lemon juice - acid
Hair and skin - acidic
An acid is a molecule or ion capable of both donating a proton, referred to as a Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis acid. the first class of acids are the proton donors, or Brønsted–Lowry acids.
An acid is any substance that in water answer tastes sour, adjusts blue litmus paper to red, reacts with a few metals to liberate hydrogen, reacts with bases to form salts, and promotes chemical reactions (acid catalysis). An acid is a substance that produces hydrogen (H+) ions when it's far delivered to water. A hydrogen ion is simply the proton and no electron
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Determine the empirical formula for dioxin (C12H4Cl4O2), a very powerful poison.
Question 4 options:
C6H2Cl2O
C12H4Cl4O2
CHClO
The empirical formula for dioxin with the molecular formula, \(C_{12}H_4Cl_4O_2\), would be \(C_6H_2Cl_2O\).
What are empirical formulas?The empirical formula of a compound is the simplest ratio of the component atoms of the compound in whole number format.
In other words, the empirical formula of a compound is the chemical formula of the compound that shows the atoms in their simplest, whole-number forms.
Empirical formulas are unlike molecular formulas. Usually, the molecular formula also shows the whole numbers of component atoms, but not in their simplest forms. Sometimes, however, the empirical and molecular formulas of a compound may be the same.
Going by these definitions, the empirical formula of dioxin whole molecular formula is, \(C_{12}H_4Cl_4O_2\) , would be \(C_6H_2Cl_2O\).
All the atoms have been reduced to their possible smallest whole-number forms by dividing them by 2.
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which of the following liquids would have the highest viscosity at the same temperature? group of answer choices ch3och3 ch3ch2nh2 ch3ch2br hoch2nh2
Since ethanol has the strongest intermolecular attractions and no other liquids have intermolecular H-bonding, ethanol has the highest viscosity.
Which molecule is more viscous, and how can you tell?Generally speaking, the viscosity of liquids increases with increasing intermolecular forces (IMF). Temperature and molecule structure are two more variables that affect viscosity. Higher average kinetic energy at higher temperatures will result in molecules moving more quickly. Lower viscosity will result from this.
What is high viscosity?The ability of a fluid to flow is determined by its viscosity. High viscosity fluids flow more slowly than low viscosity fluids due to their high resistance. In general terms, a fluid's viscosity decreases the more easily it travels.
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BIOCHEMISTRY HELP! You and a lab partner are performing on several molecular analogs to determine Km. One is a substrate analog, one is a transition state analog, and the last is a product analog. The data you obtain shows that the three Km's are 0.0013 M, 0.025 M, and 0.0045 M (in no particular order). Given what you know about the induced-fit model of catalysis, which Km would you hypothesize to belong to which analog, and why?
Answer:
Michaelis constant is known as km which is the substrate concentration that encourages the compound to work at half maximum velocity represented by Vmax/2. Michaelis constant is inversely related to the substrate and the affinity of the enzyme.
Induced fit model: The premise of the purported induced fit hypothesis, which expresses that the attachment or association of a substrate or some other atom to an enzyme causes an adjustment to the enzyme in order to fit or restrain its activity.
In substrate, analog Km or Michaelis constant will be high as the substrate will stay because of analogs inhibit activity.
In the transitional state, analog Km will be in the middle of the substrate and product analogs. Progress state analogs are synthetic mixes with a structure catalyzed reaction that looks like the progressing condition of a substrate atom in a compound enzyme.
In item simple thus Km is the least.
0.0013 M = product ananlog,
0.025 M=Transition state, and
0.0045 M = Substrate analog
Does a reaction occur when aqueous solutions of copper(II) nitrate and calcium chloride are combined
Answer:
Does a reaction occur when aqueous solutions of copper(II) nitrate and calcium chloride are combined?
Explanation:
The given reaction is an example of a chemical double displacement reaction.
The mutual interchange of the ions takes place.
The balanced chemical equation of the reaction is:
\(Cu(NO_3)_2(aq)+CaCl_2(aq) -> Ca(NO_3)_2(aq)+CuCl_2(aq)\)
All the products formed are also highly soluble.
So, all the ions are spectator ions.
Hence, all will cancel with each other and ions remain in the net ionic equation and hence, the reaction does not take place.