How many molecules are present in 0.20 g of Hydrogen gas? Select the correct option.
Correct answer: A. 0.20 x 3.01 x 10^23
- A. 0.20 x 3.01 x 10^23
- B. 0.20 x 2.016
- C. 0.70 x 6.02 x 10^23
- D. 1.008 x 6.02 x 10^23
Explanation
To find the number of molecules in 0.20 g of hydrogen gas, first recognize that hydrogen gas (H2) is diatomic. This means that 1 mole of hydrogen gas, which weighs 2.016 g, contains 6.02 x 1023 molecules. Therefore, 1 g of hydrogen gas contains 3.01 x 1023 molecules. To find the number of molecules in 0.20 g, multiply 0.20 by 3.01 x 1023, yielding 0.20 x 3.01 x 1023 molecules.Option A correctly uses this method. Option B fails by using the molar mass without Avogadro's number, Option C uses an incorrect proportion, and Option D uses the atomic mass of hydrogen instead of the diatomic gas.
Last updated
About Moles and Avogadro's Number
The mole connects the microscopic number of particles with measurable mass, using Avogadro's number, 6.022 × 10²³ particles per mole. Questions involve molar mass, conversion between mass, moles and particles, percentage composition, empirical and molecular formulas, and distinguishing atoms, molecules, ions and formula units.
Practise Fundamental Concepts of Chemistry
894 free Fundamental Concepts of Chemistry MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Chemistry questions like this
Chemistry is on 12 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
0.5 mole of nitrogen gas and 0.5 mole of carbon monoxide gas at STP have same_____________?
1 a.m.u =__________________?
1 amu is equal to 1.661 x 10^-24g, then 1.0 g will be equal to:
1 molar solution of glucose in water contains weight of glucose________________?
10 L of Cl2 gas reacts with 40L of H2 gas under same condiitions of temperature and pressure. How much volume of HCl should be produced?