When water at 50 C is added to ice at -12 C, heat is transferred from hot water to ice.
- Heat given out by water = Heat absorbed by ice
Calculating the heat released by hot water:
ΔT

Calculating heat absorbed by 16 g of ice: Ice at
is converted to ice at
and then ice at
to water at 
ΔT + 
+ 
q = 405.12 J +5336.8 J =5741.92 J
- Heat given out by water = Heat absorbed by ice
-(
m = 27.4 g
Therefore, 27.4 g water at
must be added to 16 g of ice at
to convert to liquid water at 
Answer:
The percent recovery from re crystallization for both compounds A and B is 69.745 and 81.44 % respectively.
Explanation:
Mass of compound A in a mixture = 119 mg
Mass of compound A after re-crystallization = 83 mg
Percent recovery from re-crystallization :

Percent recovery of compound A:

Mass of compound B in a mixture = 97 mg
Mass of compound B after re-crystallization = 79 mg
Percent recovery of compound B:

Explanation:
No of molecules=0.500×6.023×10²³=3.011×10²³ molecules
Answer:
Option D is correct = 8.12 grams of NaCl
Explanation:
Given data:
Moles of sodium chloride = 0.14 mol
Mass of sodium chloride = ?
Solution:
Formula:
Number of moles = mass of NaCl / Molar mass of NaCl
Molar mass of NaCl = 58 g/mol
Now we will put the values in formula.
0.14 mol = Mass of NaCl / 58 g/mol
Mass of NaCl = 0.14 mol × 58 g/mol
Mass of NaCl = 8.12 g of NaCl
Thus, 0.14 moles of NaCl contain 8.12 g of NaCl.