Plastic wrap is a substance
I'll be less soluble when the temperature increases
Answer:
<u>1.4 M</u>
Explanation:
n(HBr)=3.115/81
so, 3.115/81=0.0385mol
according to the reaction, n(HBr)=n(KOH)=0.038 mol
C(KOH)=n/V=0.0385/0.02745
0.0385/0.02745 =1.4 M
in short the answer is 1.4 M (molarity)
Answer: 2. cannot be an element.
Explanation:
Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Copper 
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: methane 

Thus as it can be decomposed into its constituent elements, it is a compound.
Mixture is a substance which has two or more components which do not combine chemically and do not have any fixed ratio in which they are present.
Thus methane cannot be an element.
Uncertainty of the data hope its help you