Molar Mass | MCQs

Explanation

The mass of one mole of electrons is 0.55g.      

- Mass of one electron ≈ 9.109 × 10⁻³¹ kg

- 1 mole of electrons = 6.022 × 10²³ electrons

- So, mass of 1 mole of electrons ≈  

  9.109 × 10⁻³¹ kg × 6.022 × 10²³ ≈ 5.48 × 10⁻⁴ kg ≈ 0.548 g

So the correct value is about 0.55 g

Explanation

Molar mass of sodium hydroxide (NaOH) = 23 (Na) + 16 (O) + 1 (H) = 40 g/mol

- For 2 moles: 40 g/mol × 2 = 80 grams

Explanation

One mole of any compound contains 6.02x10^23 molecules of that compound. 

In one molecule of SO2, there is one sulfur atom and two oxygen atoms. 

Therefore, one mole of SO2 contains 6.02x10^23 sulfur atoms. 

Explanation

The molar mass of calcium carbonate is calculated as: 

Ca=40g/mol,C=12g/mol,O₃=48g/mol 

Total=40+12+48=100g/mol