Before starting, we will convert all the givens into standard units as follows:
1.8 * 10^14 KJ/sec = 1.8 * 10^14 * 1000 = 1.8 * 10^17 J/sec
24 hours = 24 * 60 * 60 = 86400 second
Now, we are given that:
The earth receives 1.8 * 10^17 J/sec. We will begin by calculating the total energy received by the earth in 24-hours
Total energy = 1.8 * 10^17 * 86400 = 1.5552 * 10^22 Joules
Then we will get the mass from the following rule:
E = m * c^2 where:
E is the total energy = 1.5552 * 10^22 Joules
m is the mass we need to find
c is the speed of light = 3 * 10^8 m/sec
Substitute with the givens to get the mass as follows:
1.5552 * 10^22 = m * (3*10^8)^2
m = 172800 kg
The dissociation of both salts NaCl and CaCl₂ are as follows;
NaCl --> Na⁺ + Cl⁻
CaCl₂ --> Ca²⁺ + 2Cl⁻
the molar ratio of NaCl to Cl⁻ is 1:1
therefore number of NaCl moles is equal to number of Cl⁻ ions dissociated from NaCl
then number of Cl⁻ ion moles - 0.233 mol/L x 0.1000 L = 0.0233 mol
molar ratio of CaCl₂ to Cl⁻ ions is 1:2
1 mol of CaCl₂ gives out 2 mol of Cl⁻ ions.
number of CaCl₂ moles - 0.150 mol/L x 0.2500 L = 0.0375 mol
then the number of Cl⁻ ion moles - 0.0375 x 2 = 0.0750
total number of Cl⁻ ion moles = 0.0233 mol + 0.0750 mol = 0.0983 mol
volume of solution - 100.0 + 250.0 = 350.0 mL
concentration of Cl⁻ = 0.0983 mol / 0.3500 L = 0.281 M
concentration of Cl⁻⁻ is 0.281 M
