CuCl2 + 2NaNO3 ----> Cu(NO3)2 + 2NaCl
using molar masses:-
Theoretical yields:-
63.54 + 2(35.45) g of CuCl2 produces 2(22.98 + 35.45) g of NaCl
134.44 g .................................................... 116.86 g
31.0 g ....................................................31.0 * 116.86 /134.44=26.95g
So percentage yield is 21.2* 100 / 26.95 = 78.7% to nearest tenth
The average speed is 0.28
Answer: Because water has a high specific heat capacity due to the hydrogen bonding within the H₂O molecules ; so it takes a great deal of energy, or heat, to break these bonds— or to form them.
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So you have evidence that the experiment is true or correct.