Answer:
The correct answer is B) it helps to ensure the result are consistent and repeatable.
Explanation:
Scientist generally repeat an experiment if he or she did not make a mistake in the first one to compare the results of two experiment, if there is no difference in the result or values obtainted from the observation of two experiment. he or she become sure that experiment was done in a right way because if there is some error made when experiment was carried out then the result of two same experiment would be different.
It’s easy, if the PH of any acidic solution = -Log[H+], where [H+] is hydrogen ion concentration, multiply each term by (-1) then raise each term as a power to (10), so it will become like this:-
[H+] = 10^(-PH)
Answer: C. no new substances
are formed<span>
</span><span>
<span>In the
physical change of matter, there is no new substance that is formed. It is only
the appearance of the matter that is being changed and not its chemical
composition. Cutting, tearing and grinding are only some of the examples that
exhibit physical change. </span></span>
Answer:
2.5×10^-7mol/dm^3
Explanation:
Firstly convert the cm^3 to dm^3
200×1000=200000dm^3
Calculate the g/dm^3
2/200000=0.00001g/dm^3
To calculate mol/dm^3
Mol/dm^3=mass given\molar mass
=0.00001/40
=2.5×10^-7mol/dm^3
Answer:
a reactant is a substance that is at the beginning of a Chemical reaction while a product is a substance that is present at the end of a chemical reaction.in other words a reactant is a substance used up in a chemical reaction to produce something while a reactant is what is produced after a chemical reaction.
I hope this helps
