Chemistry Middle School

Suppose a snack bar is burned in a calorimeter and heats 2,000 g water by 20 °C. How much heat energy was released? (Hint: Use the specific heat equation.) Give your answer in both joules and calorie

Answers

Answer 1

Answer:

Explanation:

Remember that the key is the water so

using the formula q=m*s*deltT

We have the mass 2000g

we have the specific heat of water which is 1.00 cal/ g C

and the final temperature 20 C

Remember that delt T is the change in temperature meaning (Tfinal - Tinitial) Assuming that the water is at room temperature (25 C) before starting the reaction then

q= (2000 g)(1.00 cal/g C)(20-25)

q= -10, 000 cal

if you want you can convert to joules by multiplying by 4.314 J

In more simpler terms - If all the heat released was absorbed by the water, and it takes 1 calorie of heat to raise

the temperature of 1 gram of water by 1°C that is a total of 20 times 2000 or 40,000 cal.

or 40 kilocalories. If you want it in joules, there are 4.184 joules to one calorie so it is

4.184 times 40 or 167.36 kilojoules.

Hope that helped

Answer 2

A snack that, when burned, heats 2,000 g of water by 20 °C, releases 4.0 × 10⁴ cal (1.7 × 10⁵ J).

A snack bar is burned in a calorimeter and heats 2,000 g (m) of water by 20 °C (ΔT).

We can calculate the heat absorbed by the water (Qw) using the following expression.

$Qw = c \times m \times \Delta T = \frac{1cal}{g.\° C } \times 2,000 g \times 20 \° C = 4.0 \times 10^{4} cal$

where,

c: specific heat capacity of water

According to the law of conservation of energy, the sum of the heat absorbed by the water (Qw) and the heat released by the combustion (Qc) is zero.

$Qw + Qc = 0\\\\Qc = -Qw = -4.0 \times 10^{4} cal$

Finally, we can convert -4.0 × 10⁴ cal to J using the conversion factor 1 cal = 4.18 J.

$-4.0 \times 10^{4} cal \times \frac{4.18 J}{1cal} = 1.7 \times 10^{5} J$

A snack that, when burned, heats 2,000 g of water by 20 °C, releases 4.0 × 10⁴ cal (1.7 × 10⁵ J).

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Related Questions

Why are some incomplete fossils able to be pieced together? Full fossils of large animals can be found together. Hard tissue, like bone, never breaks or chips. Fossils require salt water to be preserved fully. Impressions from the skin can be preserved.

Answers

Answer:

Explanation:

The fossil record is considered to be incomplete because fossilization is a very rare phenomenon. Most organisms decompose quickly after their death, and their remains dispersed. In order for fossilization to occur, the remains have to be covered by sediments and stay undisturbed for thousands of years.

Answer:

The fossil record is considered to be incomplete because fossilization is a very rare phenomenon. Most organisms decompose quickly after their death, and their remains are dispersed. In order for fossilization to occur, the remains have to be covered by sediments and stay undisturbed for thousands of years.

Develop models bonds can be placed on a scale that ranges from 100% ionic to 100% covalent. Use what you know about the types of bonds that specific elements tend to form to place each of the following compounds in the correct location on the scale: CO2, N2 , NaF, H2O

Answers

Answer:

Bonds can be placed on a scale that ranges from 100% ionic to 100% covalent.

CO2: CO2 is a covalent compound, with each carbon atom sharing electrons with two oxygen atoms. Therefore, it can be placed closer to the 100% covalent end of the scale.

N2: N2 is a covalent compound, with each nitrogen atom sharing electrons with another nitrogen atom. Therefore, it can be placed closer to the 100% covalent end of the scale.

NaF: NaF is an ionic compound, consisting of a sodium cation (Na+) and a fluoride anion (F-). Therefore, it can be placed closer to the 100% ionic end of the scale.

H2O: H2O is a polar covalent compound, with the hydrogen atoms sharing electrons with the oxygen atom, but the electrons are not shared equally, therefore the oxygen atom has a partial negative charge and hydrogen atoms have a partial positive charge. Therefore, it can be placed closer to the middle of the scale, between ionic and covalent.

Overall, the scale can be represented as follows:

100% Ionic <-------> NaF <-------> H2O <-------> CO2 <-------> N2 <-------> 100% Covalent

I’ll give the definitions for half of them ( 2 ) CO2 is Carbon dioxide and H20 is the scientific word for Water/ Aqua

MULTIPLE CHOICE QUESTION + DIAGRAM IN PICTURE
CORRECT ANSWER = BRAINLIEST

Answers

Answer:

Explanation:

None of the other answers work with the chart correctly :)

B is the correct answer

The molecular diagram of a substance is shown above. The first picture is the substance before it was heated. The second picture is the substance after it was heated.

Which of the following state changes most likely occurred in the diagram above?
A.
liquid to solid
B.
solid to gas
C.
liquid to gas
D.
solid to liquid

Answers

D. for solids the molecules are very squished together. gas molecules don’t touch each other at all and have lots of room to move. liquids are in the middle and some touch, but aren’t as dense as solids

D.solid to liquid
It is solid first because it has no space to move but on the second one there is a lot of space and it is moving around which means it’s a liquid

What is civic expression?

Answers

Answer:

Civic expression includes all the ways citizens share their opinions and show concern for their community. It can take the form of action, such as voting, but it can also be demonstrated through writing or spoken text. It is a critical part of American society.

Explanation:

If something is related to or benefits an individual citizen, it can be described as civic. People often say that it is your civic duty to vote. The adjective civic comes from the Latin word civis, which was the word for a citizen of Ancient Rome.

Choose all the answers that apply.

Nitrogen has an atomic number of 7. Its atomic mass is 14. Nitrogen has _____.

seven electrons
seven neutrons
seven electron shells
23 neutrons
14 electrons

Please help (:

Answers

Seven electrons. The atomic number of a element is also the amount of protons and electrons it has.

As atomic Number is number of protons Or number of electrons so
N has 7 electrons
Neutrons= Mass no.- Atomic Number
= 14-7
N has 7 neutrons
N doesn’t have 7 electron shells because shell 1 can hold 2 electrons and shell 2 can hold 8 electrons
It doesn’t have 23 neutrons and 14 electrons

So, Seven Electrons and seven neutrons is correct

What landscape feature contributes to the dryness of deserts?

A. The open, flat areas of a desert prevent clouds from forming.

B. Desert canyons collect all water and funnel it out of the desert.

C. Desert lakes absorb all the water.

D. Mountains block the winds that bring rain clouds.

Answers

Answer:

As I'm Not % Sure I Can Say C & D don't seem Right, Leaving A & B Having Me to Think the Answer is A (Hope I'm Right Good-Luck)

Explanation:

Answer: Mountains block the winds that bring rain clouds.

Explanation: By acting as obstacles to the flow of air masses, mountains contribute significantly to the dryness of deserts. Orographic lifting is a process that occurs when moist air is forced to ascend as it approaches a mountain range. The moisture in the air condenses and forms clouds as the air cools as it climbs. As a result, on the windward side of the mountains, the air loses a lot of its moisture as precipitation. The air has already lost a significant amount of moisture by the time it reaches the leeward side of the mountains, creating a rain shadow effect. On the leeward side of the mountains, this impact results in a dryer area that is often a desert. Consequently, the existence of mountains influences

How many of y'all going to online school if so comment a computer emoji if not just say so

Answers

Answer:

Explanation:

ON AND OFF ONLINE SCHOOL FOR 4-5 YEARS TOTAL!!!!!!

IM GOING CRAZY...SOO STREZZED

Answer:

Yes.

Explanation:

1. Using D10W and a vial of NaCl 4 mEq/mL, how many mL of NaCl are needed to prepare 250 mL of a
D10/NS solution?
a. 4.8mL
b. 9.6ml
c. 19.6mL
d. 154mL

Answers

To prepare 250 mL of a D10/NS solution using D10W and a vial of NaCl 4 mEq/mL, you would need 9.6 mL of NaCl. Normal saline (NS) contains 154 mEq/L of sodium chloride (NaCl). To prepare 250 mL of NS, you would need 250 mL * (154 mEq/L) = 38500 mEq of NaCl. Since the vial of NaCl contains 4 mEq/mL, you would need 38500 mEq / (4 mEq/mL) = 9625 mL = 9.6 mL of NaCl. So the correct answer is b. 9.6ml.

the correct answer is A 4.8 mL

Before motorized vehicles were invented, what was one of the fastest ways to travel?
idrk why but its for my sci class

Answers

Answer:

horse and cart ig lol

Explanation:

char

They used Trains or horses

When the speed of the bottle is 2 m/s, the KE is kg m2/s2. When the speed of the bottle is 3 m/s, the KE is kg m2/s2. When the speed of the bottle is 4 m/s, the KE is kg m2/s2. When the speed of the bottle is 5 m/s, the KE is kg m2/s2. When the speed of the bottle is 6 m/s, the KE is kg m2/s2.
instructions
In this part of the experiment, you will be changing the speed of the bottle by dropping it from different heights. You will use the same mass, 0.250 kg, for each trial, so record this mass in Table B for each velocity. Then, calculate the expected kinetic energy (KE) at each velocity. Use the formula KE = mv2,
where m is the mass and v is the speed. Record your calculations in Table B of your Student Guide.

Answers

Answer:

Based on the given instructions, you need to calculate the expected kinetic energy (KE) at each velocity using the formula KE = mv^2, where m is the mass and v is the speed. The mass is given as 0.250 kg.

Table B: Calculation of Kinetic Energy (KE)

Speed (m/s)Mass (kg)KE (kg m^2/s^2)20.2500.50030.2500.75040.2501.00050.2501.25060.2501.500

To calculate the kinetic energy at each velocity, multiply the mass (0.250 kg) by the square of the velocity.

For example, when the speed of the bottle is 2 m/s: KE = (0.250 kg) * (2 m/s)^2 = 0.250 kg * 4 m^2/s^2 = 1.000 kg m^2/s^2

Perform similar calculations for the other velocities and record the results in Table B.

Answer:

Explanation:mass of the bottle in each case is M = 0.250 kg

now as per given speeds we can use the formula of kinetic energy to find it

1) when speed is 2 m/s