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

According to Avogadro’s law, equal volumes of all gases under similar conditions of temperature and pressure contain an equal number of molecules. So 150 cc of B will also contain X molecules. Hence, the number of molecules present in 75 cc of B will contain X 2 molecules.

Calculate the number of moles in 12 g of oxygen gas. [ O = 16 ]

Molecular mass = 16 × 2 = 32 g 32 g of oxygen gas → 1 mole 1 g of oxygen gas → 1 32 mole Given that 12 g of oxygen gas Number of moles = 12 32 = 0 . 375 mole

E M B I B E

Selina Icse Concise Chemistry For Class 10>Chapter 5 - Mole Concept and Stoichiometry>MISCELLANEOUS EXERCISE>Q 48

EASY

10th ICSE

IMPORTANT

Earn 100

LPG stands for liquefied petroleum gas. Varieties of LPG are marketed including a mixture of propane $(60 %)$ and butane $(40 %)$ . If $10 L$ of this mixture is burnt, find the total volume of carbon dioxide gas added to the atmosphere. Combustion reactions can be represented as:

$C_{3} H_{8} (g) + 5 O_{2} \to 3 {CO}_{2} (g) + 4 H_{2} O (g) 2 C_{4} H_{10} (g) + 13 O_{2} \to 8 {CO}_{2} (g) + 10 H_{2} O (g)$

Important Questions on Mole Concept and Stoichiometry

EASY

10th ICSE

IMPORTANT

Selina Icse Concise Chemistry For Class 10>Chapter 5 - Mole Concept and Stoichiometry>MISCELLANEOUS EXERCISE>Q 48

Calculate the percentage of nitrogen and oxygen in ammonium nitrate.[Relative molecular mass of ammonium nitrate is $80 u, H = 1 u, N = 14 u, O = 16 u$ ]