17) 8.4 / 20 x 100
18) 20 . 0.5150
19) 6,50% because (as you said) the law of definite proportions states that regardless of the amount, a compound is always composed of the same elements in the same proportion by mass
There are 1,000m is 1k. So just move the decimal one position right. 127.56m
There are 10,000cm in 1k. Move the decimal two positions right. 1275.6cm
12 % salt is present in 125 g mixture of salt and sand.
Keep in mind that the total percentage is always 100 %
Therefore, if 12 % is the salt, remaining 88 % must be
sand.
a. The amount of mixture is 125 q. Here, 12 % of 125 is
12 * 125 / 100 = 15 g of salt is present in 125 g mixture.
b. The amount of sand can be calculated similarly, 88 %
of 125 g is 88 * 125 / 100 = 110 g of sand is present in
125 g mixture.
False. A group of cells is called a tissue.
Answer: ![[OH^-] =10^{-10.75}=1.778\times 10^{-11}M](https://tex.z-dn.net/?f=%5BOH%5E-%5D%20%3D10%5E%7B-10.75%7D%3D1.778%5Ctimes%2010%5E%7B-11%7DM)
Explanation: pOH is defined as negative logarithm of hydroxide ions. More is the number of ![[OH^-]](https://tex.z-dn.net/?f=%5BOH%5E-%5D)
ions , lesser is the pOH and vice versa.
pH + pOH = 14
![10.75=-log[OH^-]](https://tex.z-dn.net/?f=10.75%3D-log%5BOH%5E-%5D)
![[OH^-] =10^{(-10.75)}=1.778\times 10^{-11}M](https://tex.z-dn.net/?f=%5BOH%5E-%5D%20%3D10%5E%7B%28-10.75%29%7D%3D1.778%5Ctimes%2010%5E%7B-11%7DM)
