Chemical Building Blocks

A balloon contains 6.02 x 10²³ of gas particles. What is the number of moles of the gas in the ballon?

• 0.5 mol

• 1.0 mol

• 3.0 mol

• 6.0 mol

The mass of eight atoms of element X is equal to the mass of two silicon atoms. X is not the actual symbol of the element. What is the relative atomic mass of element X ?

[Relative atomic mass: Si= 28]

• 3.5

• 7.0

• 14.0

• 28.0

The relative molecular mass of K₃M(CN)₆ is 329. What is the relative atomic mass of element M?

[Relative atomic mass: K= 39, C=12, N=14]

• 56

• 134

• 186

• 264

What is the number of atoms in 1.5 moles of sulphur dioxide, SO₂ ? [ Avogadro constant= 6.02x 10²³ mol^-1]

• 6.02x10²³

• 1.5x 6.02x 10²³

• 1.5 x 2 x 6.02x 10²³

• 1.5 x 3 x 6.02 x 10²³

Which statement explains that carbon-12 was chosen as a standard reference for relative atomic mass?

• Carbon forms covalent bonds with other elements

• Carbon atoms has four valence electrons

• Carbon is a solid which is easier to handle

• Among the three isotopes carbon-12, carbon-13 and carbon-14, carbon-12 is the lightest.

Which of the following gases contains 0.6 mole of atoms at room temperature and pressure?

[ Molar volume of gas= 24 dm³mol^-1 at room condition]

• 4.8 dm³ of neon

• 4.8 dm³ of nitrogen

• 4.8 dm³ of sulphur trioxide

• 4.8 dm³ of carbon dioxide

How much is the mass of nitrogen that is contained in 3.01 x 10²³ molecules of nitrogen ?

[ Relative atomic mass: N=14, N_A=6.02x 10²³ mol ^-1]

• 4 g

• 8 g

• 14 g

• 28 g

Tags

NGSS.HS-PS1-7

480 cm³ of gas R at room temperature and pressure has a mass of 0.04 g. What is the relative molecular mass of gas R?

[ Molar volume of gas at room temperature and pressure= 24 dm³ mol ^-1]

• 2

• 17

• 32

• 64

Which sample contains the same number of molecules as in 4.25 g ammonia gas? [ Relative atomic mass: H=1, N=14, O=16, Cl=35.5]

• 1.825 g hydrogen chloride gas

• 17.75 g chlorine gas

• 5.75 g nitrogen dioxide gas

• 2.25 g water

What is the number of moles of zinc chloride, ZnCl₂, in 13.6 g of zinc chloride? [ Relative atomic mass: Cl=35.5, Zn=65]

• 0.10 mol

• 0.14 mol

• 0.19 mol

• 0.21 mol