All categories

3 years ago

Calculate the heat (in calories) released when 115 g of CHCl3 changes from a liquid to a solid at

1 answer:

4 0

Answer: 8855 Joules energy is released when 115 g of $CHCl_3$ changes from a liquid to a solid at its freezing point.

Explanation:

Latent heat of freezing is the amount of heat released to convert 1 mole of liquid to solid at atmospheric pressure.

Amount of heat released to freeze 1 gram of $CHCl_3$ = 77 J/g

Mass of $CHCl_3$ given = 115 gram

Heat released when 1 g of $CHCl_3$ is freezed = 77 J

Thus Heat released when 115 g of $CHCl_3$ is freezed = $\frac{77}{1}\times 115=8855J$

Thus 8855 Joules energy is released when 115 g of $CHCl_3$ changes from a liquid to a solid at its freezing point.

You might be interested in

Please help also some of them may be multiple choice, thank you.

Maurinko [17]

Answer: what are the answers to the questions

Explanation:

5 0

3 years ago

A chemist adds 26.5g of ammonium chloride to 10g of sodium hydroxide, which follows the reaction below. Assuming the reaction go

4vir4ik [10]

Answer : The amount of reactant left in excess is 13.1075 grams.

Explanation : Given,

Mass of $NH_4Cl$ = 26.5 g

Mass of $NaOH$ = 10 g

Molar mass of $NH_4Cl$ = 53.5 g/mole

Molar mass of $NaOH$ = 40 g/mole

First we have to calculate the moles of $NH_4Cl$ and $NaOH$ .

$\text{Moles of }NH_4Cl=\frac{\text{Mass of }NH_4Cl}{\text{Molar mass of }NH_4Cl}=\frac{26.5g}{53.5g/mole}=0.495moles$

$\text{Moles of }NaOH=\frac{\text{Mass of }NaOH}{\text{Molar mass of }NaOH}=\frac{10g}{40g/mole}=0.25moles$

Now we have to calculate the limiting and excess reagent.

The balanced chemical reaction is,

$NH_4Cl+NaOH\rightarrow NH_4OH+NaCl$

From the balanced reaction we conclude that

As, 1 mole of $NaOH$ react with 1 mole of $NH_4Cl$

So, 0.25 moles of $NaOH$ react with 0.25 moles of $NH_4Cl$

From this we conclude that, $NH_4Cl$ is an excess reagent because the given moles are greater than the required moles and $NaOH$ is a limiting reagent and it limits the formation of product.

Moles of remaining excess reactant = 0.495 - 0.25 = 0.245 moles

Now we have to calculate the mass of $NH_4Cl$ .

$\text{Mass of }NH_4Cl=\text{Moles of }NH_4Cl\times \text{Molar mass of }NH_4Cl$

$\text{Mass of }NH_4Cl=(0.245mole)\times (53.5g/mole)=13.1075g$

Therefore, the amount of reactant left in excess is 13.1075 grams.

5 0

3 years ago

What is the mass of sodium (Na) in 50 grams of table salt (NaCl)? Show your work.

Anvisha [2.4K]

Answer:

19 g

Explanation:

Data Given:

Sodium Chloride (table salt) = 50 g

Amount of sodium (Na) = ?

Solution:

Molecular weight calculation:

NaCl = 23 + 35.5

NaCl = 58.5 g/mol

Mass contributed by Sodium = 23 g

calculate the mole percent composition of sodium (Na) in sodium Chloride.

Since the percentage of compound is 100

So,

Percent composition of sodium (Na) = 23 / 58.5 x 100

Percent of sodium (Na) = 39.3 %

It means that for ever gram of sodium chloride there is 0.393 g of Na is present.

So,

for the 50 grams of table salt (NaCl) the mass of Na will be

mass of sodium (Na) = 0.393 x 50 g

mass of sodium (Na) = 19 g

6 0

4 years ago

A red shift in the spectrum of the light from an object indicates the object is moving ____ you.

jek_recluse [69]

Away from you. This is known as the Doppler affect. It basically states that if an object is moving away from you the streching of the wave causes a red shift and if the object is moving towards you the compression of the waves causes a blue shift.

3 0

3 years ago

How do some deep-water bacteria in the ocean make food?

Umnica [9.8K]

Answer:

They make food by using chemosynthesis.

Explanation:

6 0

3 years ago