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The enthalpy of combustion of benzoic acid (C6H5COOH) is commonly used as the standard for calibrating constant-volume bomb calo

Anit [1.1K]

<h3>Answer:</h3>

28.96 kJ/°C

<h3>Explanation:</h3>

We are given;

Enthalpy change (ΔH) = −3226.7 kJ/mol
The reaction is exothermic since the heat change is negative;
Mass of benzoic acid = 3.1007 g
Temperature change (21.84°C to 24.67°C) = 2.83°C

We are required to find the heat capacity of benzoic acid;

<h3>Step 1: Moles of benzoic acid </h3>

Moles = Mass ÷ molar mass

Molar mass of benzoic = 122.12 g/mol

Therefore;

Moles = 3.1007 g ÷ 122.12 g/mol

= 0.0254 moles

<h3>Step 2: Determine the specific heat capacity </h3>

Heat change for 1 mole = 3226.7 kJ

Moles of Benzoic acid = 0.0254 moles

But;

Specific heat capacity × ΔT = Moles × Heat change

cΔT = nΔH

Therefore;

Specific heat capacity,c = nΔH ÷ ΔT

= (3226.7 kJ × 0.0254 moles) ÷ 2.83°C

= 28.96 kJ/°C

Therefore, the specific heat capacity of benzoic acid is 28.96 kJ/°C

7 0

4 years ago

How many moles of sodium nitrate, NaNO3, do you need to make 22.4L of oxygen gas at STP? *also if you can help with the other qu

max2010maxim [7]

<h2>Question no.18 </h2><h2>Part 1:</h2><h2>Answer:</h2>

We need 2 moles of sodium nitrate NaNO3 fro the production of one mole of oxygen gas.

<h3>Explanation:</h3>

The balanced chemical equation is:

2NaNO3 →→→→ 2NaNO2 + O2.

From the balanced chemical equation, it is obvious that for the production of One molecule of oxygen two molecules of NaNO3 breakdown.

So 22.4 L is equal to one mole.

Hence for the production of one mole of oxygen gas two moles of sodium nitrate will be needed.

<h2>Part b.</h2><h2>Answer:</h2>

The grams of NaNO3 for the production of 23.98 L of oxygen gas is 181.8786.

<h3>Explanation:</h3>

From the balanced chemical equation is:

2NaNO3 →→→→ 2NaNO2 + O2.

For the production of one mole of oxygen we need two moles of NaNO3.

So for 22. 4 L of O2 = 2 moles of NaNO3.

For:

1 L = 2/22.4

23.98 L = 2/22.4 * 23.98 = 2.14 moles.

In one mole of NaNO3, there are 84.99 grams.

So in 2.14 moles:

Mass in grams = 2.14 * 84.99 = 181.8786 g

Hence the grams of NaNO3 for the production of 23.98 L of oxygen gas is 181.8786.

<h2>Question 19</h2><h2>Part a:</h2><h2>Answer:</h2>

<u>If 48.8 L of the oxygen gas is used in the reaction then 48.8 liters of the carbon mono oxide gas will produce.</u>

<h3>Explanation:</h3>

From the balanced chemical equation:

C6H6S + 6O2 →→→→ 6CO + 3H2O + SO3

In the production of the six carbon monoxide six oxygen molecules are used up.

It means the ratio is 1 : 1.

It means the the amount of CO produced will be equal to the amount of O2 used.

So for the production of 48.8 L of carbon mono oxide production, the 48.8 L of the oxygen gas will be needed.

<h2>Part b.</h2><h2>Answer:</h2>

The 0.005648 L of the CO will produce with the use of 0.005648 L of oxygen gas.

<h3>Explanation:</h3>

From the balanced chemical equation:

C6H6S + 6O2 →→→→ 6CO + 3H2O + SO3

In the production of the six carbon mono oxide six oxygen molecules are used up.

It means the ratio is 1 : 1.

It means the the amount of CO produced will be equal to the amount of O2 used.

One mole of any gas is equal to 22.4 L.

So for the production of 0.005648 L of carbon mono oxide production, the 0.005648 L of the oxygen gas will be needed.

<h2>Part C.</h2><h2>Answer:</h2>

The 2.98 L of the carbon monoxide will be produced if we use 2.98 liters of oxygen gas.

<h3>Explanation:</h3>

From the balanced chemical equation, we can predict the amount of reactants and products in the chemical equation.

From the balanced chemical equation:

C6H6S + 6O2 →→→→ 6CO + 3H2O + SO3

In the production of the six carbon mono oxide six oxygen molecules are used up.

It means the ratio is 1 : 1.

It means the the amount of CO produced will be equal to the amount of O2 used.

One mole of any gas is equal to 22.4 L.

Hence for use of 2.97 L of oxygen gas, the 2.98 L of the carbon monoxide will be produced

7 0

3 years ago

You have a 150mL sample of an aqueous solution at 25C. It contains 15.2mg of an unknown nonelectrolyte compound. If the solution

Serga [27]

The molar mass of the compound:

If the solution has an osmotic pressure of 8.44 torr, then the molar mass of the unknown non-electrolyte is 223.14 g.

What is osmosis?

Osmosis is defined as the flow of solvent molecules through semi-permeable membrane.
Osmotic pressure is the pressure applied to stop the flow of solvent molecules.
It is a colligative property that means osmotic pressure depends on the number of solute particles .

Therefore,

π $V=inRT$ ( for electrolytes)

Where, π= Osmotic pressure

i = Van 't Hoff factor

n= moles

R= Gaseous constant = 62.363577 L torr $mol^{-1}K^{-1}$

T= Temperature

V= Volume of solution

Given:

T= 298K

V= 150 mL= 0.150 L

Given mass of unknown electrolyte= 15.2 mg = 15.2 x $10^{-3}$ g

Osmotic pressure= 8.44 torr

Molar mass= ?

For non-electrolytes:

πV = n RT

πV= $\frac{m}{M}$ RT

Calculations:

Putting the given values in the formula:

8.44 x 0.150 =15.2 x $10^{-3}$ / M x 62.36 x 298

1.266 = 282.5/M

M = 282.5/1.266

M = 223.14 g

Therefore,

The molar mass of the unknown non-electrolyte is 223.14g.

Learn more about Osmotic pressure here,

brainly.com/question/13680877

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7 0

2 years ago

7. Write a balanced chemical equation for the following reactions and label what type of reaction it is. (3 points)

slamgirl [31]

(A) Naoh + Hno3 == Nano3 + h20.
and it is acid based reaction.
(B) H + Br == Hbr. it is synthesis reaction
and it should be hydrogen gas with bromine gas if that was question then
H2 + Br2 == 2Hbr
(c) 3Agno3 + Alcl3 == Al (No3)3 + 3Agcl
it is double displacement. and we right the polyatomic ion in bracket that’s why no3 is in bracket.
please let me know if you need something

5 0

3 years ago

Read 2 more answers

WILL AD BRAINLIST write 5 sentences you have learned from observing rock samples. make sure to include what you know about your

Inessa [10]

Rocks are made of many different materials. Different types of rocks are made from different sediments. Depending on the sediment that the rock is made of depends on how strong the rock will be. There are six main types of sedimentary rocks. All of the rocks are different colors depending on the sediments it consist of.

8 0

3 years ago