Answer:
Na = 32.4% , % S = 22.6% and %O = 45.0%
Explanation:
% Na = 3.4/10.5. × 100%
= 32.4%
%S = 2.37/10.5 × 100%
= 22.6%
% O= 4.73/10.5 × 100%
= 45.0%xplanation:
<span>Heat from the can is making the water molecule move faster, which melts the ice.</span>
Option (a) is correct.
A reducing agent is the one which loses electrons to other substance.
Here, Zn has oxidation number 0 in the L.H.S of the equation, but on R.H.S its oxidation number is +2 i.e. it Zn has donated two of its electrons to

.
Hence, Zn is the reducing agent here.
Answer:
B.) If sodium carbonate is added to vinegar, the reaction will absorb heat.
Explanation:
A.) is incorrect because this is not testable. Rather, it is just an opinion that cannot be proven correct or incorrect.
B.) is correct because this statement is testable. Tests need to be run to determine the accuracy of the statement.
C.) is incorrect because this statement explains something that does not need to be tested. It is an example of a physical change when one tears a piece of paper.
D.) is incorrect because this is already a true statement. It is obvious that not all reactions absorb/release heat. While tests could be run to further prove this statement true, it is already considered accurate.