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.
Answer:
B. Molarity will decrease
Explanation:
Molarity is one of the measures of the molar concentration of a solution. It is calculated by dividing the number of moles of the solute by the volume of the solvent. This means that the higher the amount of solute in relation to the volume of solvent, the higher the molarity of that solution.
In essence, adding water to a solution dilutes it i.e it increases the solvent's volume in relation to the solute, causing the molarity to decrease. In a nutshell, diluting a solution (by adding water or more solvent) causes the molarity of such solution to decrease. For example, if water is added to a 0.70 molar solution of CuSO4, the molarity of the solution will DECREASE.
Answer:
<h2>Molarity = 7 mol / L</h2>
Explanation:
Since the mass of NaCl and it's volume has been given we can find the molarity by using the formula
<h3>

</h3>
where
C is the molarity
m is the mass
M is the molar mass
v is the volume
From the question
v = 0.5 L
m = 205 g
We must first find the molar mass and then substitute the values into the above formula
M( Na) = 23 , M( Cl) = 35.5
Molar mass of NaCl = 23 + 35.5 =
58.5 g/mol
So the molarity of NaCl is

C = 7.00854
We have the final answer as
<h3>Molarity = 7 mol / L</h3>
Hope this helps you
Answer:
C₆H₅COOH Benzoic Acid
Explanation:
Here we are using the extraction method to separate benzoic acid from naphtalene in the ether solution by reacting it with the base sodium bicarbonate to produce the salt sodium benzoate ( naphtalene remains in the organic layer ) .
The sodium benzoate is completely soluble in the aqueous layer being a salt, and reacts with hydrochloric acid ( again an acid base reaction ) which precipitates the benzoic acid since the it is insoluble in water hence separating it.