Calculate AHræn for the following reaction

The temperature of a sample of water changes from 10°C to 20°C when the water absorbs 100 calories of heat. What is the mass of

Vlad1618 [11]

Answer:

10 g

Explanation:

Right from the start, just by inspecting the values given, you can say that the answer will be

10 g

.

Now, here's what that is the case.

As you know, a substance's specific heat tells you how much heat is needed to increase the temperature of

1 g

of that substance by

1

∘

C

.

Water has a specific heat of approximately

4.18

J

g

∘

C

. This tells you that in order to increase the temperature of

1 g

of water by

1

∘

C

, you need to provide

4.18 J

of heat.

Now, how much heat would be required to increase the temperature of

1 g

of water by

10

∘

C

?

Well, you'd need

4.18 J

to increase it by

1

∘

C

, another

4.18 J

to increase it by another

1

∘

C

, and so on. This means that you'd need

4.18 J

×

10

=

41.8 J

to increase the temperature of

1 g

of water by

10

∘

C

.

Now look at the value given to you. If you need

41.8 J

to increase the temperature of

1 g

of water by

10

∘

C

, what mass of water would require

10

times as much heat to increase its temperature by

10

∘

C

?

1 g

×

10

=

10 g

And that's your answer.

Mathematically, you can calculate this by using the equation

q

=

m

⋅

c

⋅

Δ

T

, where

q

- heat absorbed/lost

m

- the mass of the sample

c

- the specific heat of the substance

Δ

T

- the change in temperature, defined as final temperature minus initial temperature

Plug in your values to get

418

J

=

m

⋅

4.18

J

g

∘

C

⋅

(

20

−

10

)

∘

C

m

=

418

4.18

⋅

10

=

10 g

5 0

3 years ago

A student draws the model shown below. Which of these best compares the conditions at Location X and Location Y?

arlik [135]

Answer:

Explanation:

You have to use formula b to your answer

5 0

3 years ago

DONT SEND LINKS OR DONT COMMENT IF YOU DONT KNOW THE ANSWER

melisa1 [442]

Most likely to be found is called an Orbital.

7 0

3 years ago

Read 2 more answers

Calculate the delta S rxn at 25 degrees celsius for the reaction 2NH3(g)->>N2H4(g) + H2(g). Do you know where I can find t

Alchen [17]

In order to find your answer you need to be <span>measuring entropy, so you will be using the following formula:
</span><span>delta S= S of (N2H4) + S of ( H2) - [2( S of NH3)]
</span>Hope this is very useful for you

3 0

3 years ago

It takes 839./kJmol to break a carbon-carbon triple bond. Calculate the maximum wavelength of light for which a carbon-carbon tr

tresset_1 [31]

Answer:

The maximum wavelength of light for which a carbon-carbon triple bond could be broken by absorbing a single photon is 143 nm.

Explanation:

It takes 839 kJ/mol to break a carbon-carbon triple bond.

Energy required to break 1 mole of carbon-carbon triple bond = E = 839 kJ

E = 839 kJ/mol = 839,000 J/mol

Energy required to break 1 carbon-carbon triple bond = E'

$E'=\frac{ 839,000 J/mol}{N_A}=\frac{839,000 J}{6.022\times 10^{23} mol^{-1}}=1.393\times 10^{-18} J$

The energy require to single carbon-carbon triple bond will corresponds to wavelength which is required to break the bond.

$E'=\frac{hc}{\lambda }$ (Using planks equation)

$\lambda =\frac{6.626\times 10^{-34} Js\times 3\times 10^8 m/s}{1.393\times 10^{-18} J}$

$\lambda =1.427\times 10^{-7} m =142.7 nm = 143 nm$

$(1 m = 10^9 nm)$

The maximum wavelength of light for which a carbon-carbon triple bond could be broken by absorbing a single photon is 143 nm.

6 0

4 years ago