3.1 RAM, RMM, RFM

Your full name.

Calculate the relative molecular mass for  $HCl$ .
[RAM: H = 1; Cl = 35.5]

• 37.5

• 36.5

• 34.5

Find the relative formula mass of  $Na_2CO_3$ .

[RAM; C = 12; O = 16; Na = 23]

• 83

• 90

• 106

Relative molecular mass of

 $X_2CO_3$  is 154. What is the relative atomic mass of element X? 
[RAM: C = 12; O = 16]

• 47

• 94

• 53

Element neon is 5 times heavier than element helium. Determine the relative atomic mass of element neon if the RAM of helium is 4.

• 16

• 20

• 5

Define the relative molecular mass of a molecule.

• The average mass of the molecule compared to 1/12 of the mass of carbon-12 atom.

• The average mass of the substance compared to 1/12 of the mass of carbon-12 atom.

• The average mass of an atom of that element compared to 1/12 of the mass of carbon-12 atom.

Which of the following(s) is/are the reason why carbon-12 chosen as the standard atom?

• It is easier to handle.

• Most abundant carbon isotope.

• Already used as the reference standard in mass spectrometer.

• It can't react or combine with other elements.

What is the relative formula mass of ammonium nitrate,  $NH_4NO_3?$  
[Relative atomic mass: N = 14; H = 1; O = 16]

• 76

• 79

• 80

• 90

What is the relative formula mass of hydrated magnesium sulphate, MgSO₄.7H₂O?

[Relative atomic mass : H = 1, O = 16, Mg = 24 , S = 32]

• 145

• 150

• 239

• 246

The relative atomic mass is the average mass of an atom compared to

• the mass of a carbon-12 atom.

• 1/12 the mass of a carbon-12 atom

• the mass of a hydrogen atom

• 1/12 the mass of a hydrogen atom