Answer: The energy (heat) required to convert 52.0 g of ice at –10.0°C to steam at 100°C is 157.8 kJ
Explanation:
Using this formular, q = [mCpΔT] and = [nΔHfusion]
The energy that is needed in the different physical changes is thus:
The heat needed to raise the ice temperature from -10.0°C to 0°C is given as as:
q = [mCpΔT]
q = 52.0 x 2.09 x 10
q = 1.09 kJ
While from 0°C to 100°C is calculated as:
q = [mCpΔT]
q = 52.0 x 4.18 x 100
q = 21.74 kJ
And for fusion at 0°C is called Heat of fusion and would be given as:
q = n ΔHfusion
q = 52.0 / 18.02 x 6.02
q = 17.38 kJ
And that required for vaporization at 100°C is called Heat of vaporization and it's given as:
q = n ΔHvaporization
q = 52.0 / 18.02 x 40.7
q = 117.45 kJ
Add up all the energy gives 157.8 kJ
Answer:
8239.2g
Explanation:
Given parameters:
Number of atoms in Br = 6.2 x 10²⁵atoms
Unknown:
Mass of Br = ?
Solution:
From mole concepts, we know that:
1 mole of a substance contains 6.02 x 10²³ atoms/mol
Molar mass of Br = 80g/mol
6.2 x 10²⁵atoms x 
x 80 x 
= 8239.2g
Answer:
CuBr₂(aq) + Pb(CH₃COO)₂(aq) → Cu(CH₃COO)₂(aq) + PbBr₂ (s)↓
Explanation:
We identify the reactants:
CuBr₂ and Pb(CH₃COO)₂
The products will be: Cu(CH₃COO)₂ and PbBr₂
You may know these information:
Salts from acetate are soluble.
Bromide can make solid salts with these cations: Ag⁺, Pb²⁺, Hg₂²⁺, Cu⁺
PbBr₂ is formed, so this will be our precipitate
The equation is:
CuBr₂(aq) + Pb(CH₃COO)₂(aq) → Cu(CH₃COO)₂(aq) + PbBr₂ (s)↓
Answer: m = 50 g ZnSO4
Explanation: First is convert the moles of Zn to the moles of ZnSO4 by having their mole ratio which is 2:2 based from the balanced equation. Next is convert the moles of ZnSO4 to mass using its molar mass.
0.311 mole Zn x 2 moles ZnSO4 / 2 moles Zn
= 0.311 moles ZnSO4
0.311 moles ZnSO4 x 161 g ZnSO4 / 1 mole ZnSO4
= 50 ZnSO4
Answer: In simplest case mass of reactants is same as mass of products.
Without thinking this question deeper, mass of ZnCl2 would be 49, but..
Explanation: Reaction should be Zn + 2 HCl ⇒ ZnCl2 + H2
Amount of zinc is 5 g / 65,38 g/mol = 0,076476 mol and amount
of Hydrogen Chloride is 50 g / 36.458 g/mol = 1,371 mol.
Althought HCl is needed 0.152 moles, zinc is an limiting reactant.
So it is possible to produce only 0.076476 mol Hydrogen and its mass
is 0.154 g. Mass of ZnCl2 would be 0.076476 mol · (65.38 + 2·35.45) =
10.42 g
