The balanced chemical equation is,
\({ CaCO }_{ 3 }\left( s \right) \overset { \triangle }{ \longrightarrow } { CaO }_{ (s) }+{ CO }_{ 2 }(g)\)
As per the stoichiometric equation,
1 mole (100g) CaC0₃ on heating produces 1 mole CO₂

At STP, 1 mole of CO₂ occupies a volume of 22.7 liters
At STP, 50 g of CaCO₃ on heating produces,

= 11.35 liters of CO₂

CH_4(g) + 2O₂ \(\rightarrow\) CO₂ + 2H₂O
16g                          (2x18)g
As per stoichiometric equation,
16 g of methane produces 36 g of H₂O
\(\therefore\) 32 g of methane will produce = \(\frac { 36 }{ 16 } \times 32=72\) g of water.

The balanced equation for the combustion of ethane
C₂H₆ + \(\frac { 7 }{ 2 } \)O₂ \(\longrightarrow \) 2CO₂ +3H₂O
2C₂H₆ + 7O₂ \(\longrightarrow \) 4CO₂ + 6H₂O
To produce 4 moles of CO₂, 2 moles of ethane is required
To produce 1 moles (44 g) of CO₂ required
Number of moles of ethane
\(=\frac{2 \mathrm{~mol} \text { ethane }}{4 \not \mathrm{molCO}_{2}} \times 1 \not \mathrm{molCO}_{2}\)
= \(\frac { 1 }{ 2 } mole\quad of\quad ethane\)
= 0.5 mole of ethane

1) The unit of molecular mass is atomic mass unit [amu]. The unit of molar mass is gram per mole.
2) Molecular mass is the mass of one molecule while molar mass is the mass of one mole of molecules (6.022 x 10²³)
(i) Molecular mass of CO₂ = 1(C) + 2(0) = 12 + 32 = 44 amu
or 7.304 x 10^-23 g
(ii) Molar mass of CO₂ = 44 g mol^-1.

Question	Number of moles of reactants allowed to react			Number of moles reactants consumed during reaction			Limiting reagent
	x	y	z2	x	y	z2
(a)	200 atoms	200 atoms	50 molecules	50 atoms	50 atoms	50 molecules	z2

ii) 1 mol of x + 1 mol of y + 3 mol of z₂

Question	Number of moles of reactants allowed to react			Number of moles reactants consumed during reaction			Limiting reagent
	x	y	z2	x	y	z2
(a)	1 mol	1 mol	3 mol	1 mol	1 mol	1 mol	x and y

ii) 50 atoms of x + 25 atoms of y + 50 molecules of z₂

 

Question	Number of moles of reactants allowed to react			Number of moles reactants consumed during reaction			Limiting reagent
	x	y	z2	x	y	z2
(a)	50 atom	25 atom	50 molecules	25 atom	25 atom	25 molecules	y

iv)  2.5 mol of x + 5 mol of y + 5 mol of z₂

 

Question	Number of moles of reactants allowed to react			Number of moles reactants consumed during reaction			Limiting reagent
	x	y	z2	x	y	z2
(a)	2.5 mol	5 mol	5 mol	2.5 mol	2.5 mol	2.5 mol	x