It's because of Avagadro's number.
- It is known as Avagadro's constant too.
- It states that at constant temperature one mole of any substance contain same number of atoms i.e n no of atoms
where

<span>If the aqueous solution is 34% Licl then it is 100 - 34% water = 66%
From the calculation we've found out that it is 66% water. Then we need to find the weight from a 250 g solution.
66/100 * 250 = 165g
Hence it is 165g</span>
Solve these problems like weighted averages:
The first one:
Multiply the masses (isotope numbers) by the decimal form of the percentage. Add them
0.076 (6) + 0.924 (7) = 6.924
The second one:
0.2 (10) + 0.8 (11) = 10.8
If you think about it, these answers make sense. 6.924 is much closer to 7 than to 6 (since there's a lot more lithium-7 than there is lithium-6). 10.8 is closer to 11 than to 10.
Dilution of the solution can be calculated by the formula of the molarity and volume. The initial volume of 2.50 M solution was 30 mL.
<h3>What is the relationship between molar concentration and dilution?</h3>
Molar concentration or the dilution factor is in an inverse relationship and with an increase in the dilution, the molarity of the solution decreases.
Given,
Initial molarity = 2.50 M
initial volume = ?
Final molarity = 0.750 M
Final volume = 100.0 ml
Substituting values in the formula:

Therefore, 30 mL was the initial volume of the solution before it was diluted.
Learn more about dilution here:
brainly.com/question/26896011
Answer:
A. It is possible not all of the water was evaporated from the sand, causing the recovered mass to be higher
D. While drying the NaCl, the liquid boiled and some splattered out of the evaporating dish, causing the recovered mass to be higher.
Explanation:
Sand absorbs water and stores it. The sunlight causes the water to evaporate but sand can hold some of the water inside it. This results in increase in mass of the sand. The mass of sand before and after the water evaporation can be different.