Answer:
11.99
% ≅ 12.0%.
Explanation:
∵ mass % = [mass of solute/mass of solution] x 100.
mass of solute (CaCl₂) = 8.87 g & mass of solution = 8.87 g + 65.1 g = 73.97 g.
<em>∴ mass % of (CaCl₂) = [mass of solute/mass of solution] x 100 </em>= (
8.87 g/ 73.97 g) x 100 = <em>11.99
% ≅ 12.0%.</em>
It's Synthesis, single replacement is incorrect.
Answer : The reaction is endothermic.
Explanation :
Formula used :

where,
= change in temperature = 
Q = heat involved in the dissolution of KCl = ?
m = mass = 0.500 + 50.0 = 50.5 g
c = specific heat of resulting solution = 
Now put all the given value in the above formula, we get:


The heat involved in the dissolution of KCl is positive that means as the change in temperature decreases then the reaction is endothermic and as the change in temperature increases then the reaction is exothermic.
Hence, the reaction is endothermic.
<span>work = force x distances </span>
<span>A - moving 2 newton's up 0.6 meter = 1.2 joules
B - moving 4 newton's up 0.6 meter = 2.4 joules
C - moving 6 newton's up 0.3 meter = 1.8 joules
D - moving 9 newton's up 0.3 meter = 2.7 joules
The greatest amount of work is in example D.
</span>
<span>
D is your answer. </span>