Aluminium carbide reacts with water according to the following equation. Al 4 C 3 + 12 H 2 O → 4 A l O H 3 + 3 C H 4 What mass of aluminum hydroxide is formed from 12 g of aluminum carbide?

Atomic masses of elements are: Al = 27 C = 12 O = 16 H = 1 From the above reaction, molar mass of A l 4 C 3 = 144 g / mol Molar mass of A l O H 3 = 78 g / mol Amount of aluminium hydroxide formed from 144 g of aluminium carbide = 312 g So, the amount of aluminium hydroxide formed from 12 g of aluminium carbide= 4 × 78 × 12 144 = 26 g

Aluminium carbide reacts with water according to the following equation. Al 4 C 3 + 12 H 2 O → 4 A l O H 3 + 3 C H 4 What volume of methane at S T P is obtained from 12 g of aluminium carbide? (Relative molecular weight of Al 4 C 3 = 144 , A l O H 3 = 78 )

Al 4 C 3 + 12 H 2 O → 4 Al OH 3 + 3 CH 4 From the above reaction, we can conclude that 144 g of Al 4 C 3 gives 48 g of CH 4 Therefore, 12 g of Al 4 C 3 gives= 12 × 48 144 g of CH 4 = 4 g of CH 4 We know that 1 mole of any gas at STP occupies a volume of 22 . 4 L Therefore, volume occupied by 4 grams of methane= 4 16 × 22 . 4 = 5 . 6 L .

Ethane burns in oxygen to form C O 2 and H 2 O according to the equation, 2 C 2 H 6 + 7 O 2 → 4 C O 2 + 6 H 2 O If 1 250 c c of oxygen is burnt with 300 c c of ethane. Calculate the volume of C O 2 formed.

2 C 2 H 6 + 7 O 2 → 4 C O 2 + 6 H 2 O According to the above reaction where ethane burns in the presence of oxygen, 2 volumes of ethane reacts with oxygen to give 4 volumes of carbon dioxide. This means the volume of carbon dioxide formed is two times the volume of ethane. So the volume of carbon dioxide formed from 300 cc of ethane would be two times the amount of ethane = ( 300 × 2 ) cc Therefore, the amount of carbon dioxide formed from 300 cc of ethane is 600 cc .

Ethane burns in oxygen to form C O 2 and H 2 O according to the equation, 2 C 2 H 6 + 7 O 2 → 4 C O 2 + 6 H 2 O If 1 250 c c of oxygen is burnt with 300 c c of ethane. Calculate the volume of unused O 2 .

2 C 2 H 6 + 7 O 2 → 4 CO 2 + 6 H 2 O In the balance equation given, the number of moles of oxygen is 3 . 5 times the number of moles of ethane. Hence, the volume of oxygen will also be 3 . 5 times the amount of ethane. To burn 300 cc of ethane, the amount of oxygen needed = 3 . 5 × 300 = 1050 cc The amount of oxygen burnt with 300 cc of ethane in the given question= 1250 cc Hence, the amount of unused oxygen 1250 - 1050 cc = 200 cc of oxygen.

Propane burns in air according to the following equation C 3 H 8 + 5 O 2 → 3 C O 2 + 4 H 2 O . What volume of propane is consumed on using 1000 c m 3 of air considering only 20 % of air contains oxygen?

C 3 H 8 + 5 O 2 → 3 C O 2 + 4 H 2 O Volume of air = 1000 c m 3 ; % of oxygen in air = 20 % Since, only 20 % of oxygen is present in 1000 cm 3 , the volume of oxygen in air = 20 100 × 1000 = 200 cm 3 The volume of propane burnt for every 200 c m 3 of oxygen = 1 5 × 200 = 40 c m 3 .

Ethane burns in oxygen to form C O 2 and H 2 O according to the equation, 2 C 2 H 6 + 7 O 2 → 4 C O 2 + 6 H 2 O If 1 250 c c of oxygen is burnt with 300 c c of ethane. Calculate the volume of C O 2 formed.

2 C 2 H 6 + 7 O 2 → 4 C O 2 + 6 H 2 O According to the above reaction where ethane burns in the presence of oxygen, 2 volumes of ethane reacts with oxygen to give 4 volumes of carbon dioxide. This means the volume of carbon dioxide formed is two times the volume of ethane. So the volume of carbon dioxide formed from 300 cc of ethane would be two times the amount of ethane = ( 300 × 2 ) cc Therefore, the amount of carbon dioxide formed from 300 cc of ethane is 600 cc .

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A $3 g$ sample of ${Na}_{2} {CO}_{3} . 10 H_{2} O$ is heated to a constant mass. How much anhydrous salt remains?

Important Questions on Mole Concept and Stoichiometry

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All in One - ICSE Chemistry>Chapter 5 - Mole Concept and Stoichiometry>CHAPTER EXERCISE>Q 28

The following reaction takes place as

${Pb}_{3} O_{4} + 8 HCl \to 3 {PbCl}_{2} + 4 H_{2} O + {Cl}_{2}$

Calculate

(i) mass of lead chloride formed by the action of $6.85 g$ of red lead( ${Pb}_{3} O_{4}$ );

(ii) the mass of chlorine;

(iii) the volume of chlorine evolved at STP.

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All in One - ICSE Chemistry>Chapter 5 - Mole Concept and Stoichiometry>ARCHIVES*(Last 7 Years)>Q 1

The percentage composition of a gas is nitrogen -

82.35 %

, hydrogen -

17.64 %

.
Find the empirical formula of the gas.

[N = 14, H = 1]

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All in One - ICSE Chemistry>Chapter 5 - Mole Concept and Stoichiometry>ARCHIVES*(Last 7 Years)>Q 1

Aluminium carbide reacts with water according to the following equation.

{Al}_{4} C_{3} + 12 H_{2} O \to 4 A l {(O H)}_{3} + 3 C H_{4}

What mass of aluminum hydroxide is formed from

12 g

of aluminum carbide?

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10th ICSE

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All in One - ICSE Chemistry>Chapter 5 - Mole Concept and Stoichiometry>ARCHIVES*(Last 7 Years)>Q 1

Aluminium carbide reacts with water according to the following equation.

{Al}_{4} C_{3} + 12 H_{2} O \to 4 A l {(O H)}_{3} + 3 C H_{4}

What volume of methane at

S T P

is obtained from

12 g

of aluminium carbide?
(Relative molecular weight of

{Al}_{4} C_{3} = 144, A l {(O H)}_{3} = 78

)

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All in One - ICSE Chemistry>Chapter 5 - Mole Concept and Stoichiometry>ARCHIVES*(Last 7 Years)>Q 1

If $150 c c$ of gas, $A$ contains $X$ molecules, how many molecules of gas $B$ will be present in $75 c c$ of $B$ ? The gases $A$ and $B$ are under the same temperature and pressure. Name the law on which the above problem is based?

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All in One - ICSE Chemistry>Chapter 5 - Mole Concept and Stoichiometry>ARCHIVES*(Last 7 Years)>Q 2

Ethane burns in oxygen to form

{C O}_{2}

and

H_{2} O

according to the equation,

2 C_{2} H_{6} + 7 O_{2} \to 4 {C O}_{2} + 6 H_{2} O

1250 c c

of oxygen is burnt with

300 c c

of ethane. Calculate the volume of

{C O}_{2}

formed.

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10th ICSE

IMPORTANT

All in One - ICSE Chemistry>Chapter 5 - Mole Concept and Stoichiometry>ARCHIVES*(Last 7 Years)>Q 2

Ethane burns in oxygen to form

{C O}_{2}

and

H_{2} O

according to the equation,

2 C_{2} H_{6} + 7 O_{2} \to 4 C O_{2} + 6 H_{2} O

1250 c c

of oxygen is burnt with

300 c c

of ethane. Calculate the volume of unused

O_{2}

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10th ICSE

IMPORTANT

All in One - ICSE Chemistry>Chapter 5 - Mole Concept and Stoichiometry>ARCHIVES*(Last 7 Years)>Q 3

Propane burns in air according to the following equation
$C_{3} H_{8} + 5 O_{2} \to 3 {C O}_{2} + 4 H_{2} O$ .

What volume of propane is consumed on using $1000 {c m}^{3}$ of air considering only $20 %$ of air contains oxygen?

A 3g sample of Na2CO3.10H2O is heated to a constant mass. How much anhydrous salt remains?

Important Questions on Mole Concept and Stoichiometry

Learn and Prepare for any exam you want !

A $3 g$ sample of ${Na}_{2} {CO}_{3} . 10 H_{2} O$ is heated to a constant mass. How much anhydrous salt remains?