Answer:- 1.90 atm
Solution:- It is based on combined gas law equation, PV = nRT
In this equation, P is pressure, V is volume, n is moles of gas, R is universal gas constant and T is kelvin temperature.
If we divide both sides by V then:

We know that, molarity is moles per liter. So, in the above equation we could replace
by molarity, M of the gas. The equation becomes:
P = MRT
T = 20 + 273 = 293 K
M = 
Let's plug in the values in the equation:
P = 
P = 1.90 atm
So, the pressure of the gas is 1.90 atm.
Ocean tides are caused by mostly wind but can also be caused by earthquakes
Answer:
Quartz.
Explanation:
According to the characteristics given in the question the mineral must surely be Quartz.
Quartz does not react with hydrochloric acid.
Its is pink in color and has anon metallic luster. It has a specific gravity of 2.65. Quartz is continuous framework of SiO4 , with each oxygen being shared with two tetrahedra, giving an overall chemical formula of SiO2.
% by mass = (mass solute/mass solution)*100%
mass of the solute = 54.7 g
mass of the solution = mass solute + mass solvent=54.7+500=554.7 g
% by mass = (54.7/554.7)*100%≈0.0986*100% = 9.86%
Answer : The mass of oxygen will be, 36.8 grams
Solution : Given,
Moles of water = 2.30 moles
Molar mass of
= 32 g/mole
First we have to calculate the moles of oxygen.
The balanced chemical reaction will be,

From the balanced reaction we conclude that
2 moles of water decomposes to give 1 mole of 
2.30 moles of water decomposes to give
moles of 
Now we have to calculate the mass of oxygen.


Therefore, the mass of oxygen will be, 36.8 grams