Answer:
you can now deduct which one is greater or smaller and by how much.
Explanation:
no of moles= mass/molar mass
1ai) 0.4 = m/ ( 12 + (16*2)
m= 0.4* 44
m= 17.6g
ii) 0.6= m/( 2*1 + 16)
m= 0.6 *18
m= 10.8g
b) 0.135 = m/ ( 2*1 +32 + (16*4)
m= 0.135* 98
m= 13.23g
ii) 0.5= m/ (1+35.5)
m= 0.5*36.5
m= 18.25g
2. Avogadro's Number = 6.02×10²³
1 mol of any element= 6.02×10²³ particles
a) 0.1 mol of H20= (6.02×10²³) * 0.1
= 6.02×10²² molecules
ii) 0.3 mol of CO2= (6.02×10²³) * 0.3
= 1.806 × 10²³ molecules
Ans: 0.3 mol of CO2
bi) 0.25 mol of HCl= (6.02×10²³) * 0.25
= 1.505 × 10²³ molecules
bii) - find the no of moles first:
no of moles= mass/molar mass
n= 3.4g/ 34g →mr of H2S in g=2+32= 34g
n= 0.l mol
- use the Avogadro Number.
0.1 mol of H20= (6.02×10²³) * 0.1
= 6.02×10²² molecules.
biii) here you're given the density, use it to find the mass of acetic acid.
ρ = 1049 g/ml
ρ = m/v, where v=5 ml
1049 = m/ 5
m= ρ*v
m= 1049*5
m= 5245 g
• convert this into moles.
mr of CH3COOH= 12 + 3+ 12+ 16+ 16+ 1
= 60
mr in g = 60g
n= m/mr
n= 5245/ 60
n= 87. 41666...
n= 87.4 moles
•using Avogadro's Number:
87.4 moles of acetic acid=(6.02×10²³)*87.4
= 2.25148* 10²⁵
= 2.25 * 10²⁵ molecules
thus, the ans for this is 5 ml of acetic acid.
