Answer:
The molarity (M) of the following solutions are :
A. M = 0.88 M
B. M = 0.76 M
Explanation:
A. Molarity (M) of 19.2 g of Al(OH)3 dissolved in water to make 280 mL of solution.
Molar mass of Al(OH)3 = Mass of Al + 3(mass of O + mass of H)
= 27 + 3(16 + 1)
= 27 + 3(17) = 27 + 51
= 78 g/mole
= 78 g/mole
Given mass= 19.2 g/mole
![Mole = \frac{Given\ mass}{Molar\ mass}](https://tex.z-dn.net/?f=Mole%20%3D%20%5Cfrac%7BGiven%5C%20mass%7D%7BMolar%5C%20mass%7D)
![Mole = \frac{19.2}{78}](https://tex.z-dn.net/?f=Mole%20%3D%20%5Cfrac%7B19.2%7D%7B78%7D)
Moles = 0.246
![Molarity = \frac{Moles\ of\ solute}{Volume\ of\ solution(L)}](https://tex.z-dn.net/?f=Molarity%20%3D%20%5Cfrac%7BMoles%5C%20of%5C%20solute%7D%7BVolume%5C%20of%5C%20solution%28L%29%7D)
Volume = 280 mL = 0.280 L
![Molarity = \frac{0.246}{0.280)}](https://tex.z-dn.net/?f=Molarity%20%3D%20%5Cfrac%7B0.246%7D%7B0.280%29%7D)
Molarity = 0.879 M
Molarity = 0.88 M
B .The molarity (M) of a 2.6 L solution made with 235.9 g of KBr
Molar mass of KBr = 119 g/mole
Given mass = 235.9 g
![Mole = \frac{235.9}{119}](https://tex.z-dn.net/?f=Mole%20%3D%20%5Cfrac%7B235.9%7D%7B119%7D)
Moles = 1.98
Volume = 2.6 L
![Molarity = \frac{Moles\ of\ solute}{Volume\ of\ solution(L)}](https://tex.z-dn.net/?f=Molarity%20%3D%20%5Cfrac%7BMoles%5C%20of%5C%20solute%7D%7BVolume%5C%20of%5C%20solution%28L%29%7D)
![Molarity = \frac{1.98}{2.6)}](https://tex.z-dn.net/?f=Molarity%20%3D%20%5Cfrac%7B1.98%7D%7B2.6%29%7D)
Molarity = 0.762 M
Molarity = 0.76 M
The ocean hold 97 percent of earths water.