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>EXERCISE-5B>Q 23

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IMPORTANT

Earn 100

If phosphorus is considered to contain $P_{4}$ molecules, then calculate the number of moles in $100 g$ of phosphorus.

Important Questions on Mole Concept and Stoichiometry

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IMPORTANT

Selina Icse Concise Chemistry For Class 10>Chapter 5 - Mole Concept and Stoichiometry>EXERCISE-5B>Q 24

Calculate the gram molecular mass of chlorine if $308 {cm}^{3}$ of it at STP weighs $0.979 g$ .

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IMPORTANT

Selina Icse Concise Chemistry For Class 10>Chapter 5 - Mole Concept and Stoichiometry>EXERCISE-5B>Q 24

Calculate the volume of

4 g

of

H_{2}

at

4

atmosphere.

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Selina Icse Concise Chemistry For Class 10>Chapter 5 - Mole Concept and Stoichiometry>EXERCISE-5B>Q 24

Calculate the mass of oxygen in $2.2$ litres of ${CO}_{2}$ at STP.

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Selina Icse Concise Chemistry For Class 10>Chapter 5 - Mole Concept and Stoichiometry>EXERCISE-5B>Q 25

A student puts his signature with a graphite pencil. If the mass of carbon in the signature is 10^-12g, calculate the number of carbon atoms in the signature.

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Selina Icse Concise Chemistry For Class 10>Chapter 5 - Mole Concept and Stoichiometry>EXERCISE-5B>Q 26

An unknown gas shows a density of $3$ gram per litre at $273 ° C$ and $1140 mm$ $Hg$ pressure. What is the gram molecular mass of this gas?

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Selina Icse Concise Chemistry For Class 10>Chapter 5 - Mole Concept and Stoichiometry>EXERCISE-5B>Q 27

Cost of Sugar ( $C_{12} H_{22} O_{11}$ ) is ₹ $40$ per $kg$ . Calculate its cost per mole.

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