Pb/pbco3*100
207/207+12+48
207/267*100
=77.53%
Since greenhouses are designed to trap in heat, we call global warming the “greenhouse effect” because it essentially does the same thing. “Greenhouse” gases (gases that easily trap heat) clog up the outer layers of the atmosphere and prevents heat from leaving the planet. The gases trap heat, just like greenhouses.
Answer: -
15.55 M
35.325 molal
Explanation: -
Let the volume of the solution be 1000 mL.
Density of nitric acid = 1.42 g/ mL
Total Mass of nitric acid Solution = Volume of nitric acid x Density of nitric acid
= 1000 mL x 1.42 g/ mL
= 1420 g.
Percentage of HNO₃ = 69%
Amount of HNO₃ = 
= 979.8 g
Molar mass of HNO₃ = 1 x 1 + 14 x 1 + 16 x 3 = 63 g /mol
Number of moles of HNO₃ = 
= 15.55 mol
Molarity is defined as number of moles per 1000 mL
We had taken 1000 mL as volume and found it to contain 15.55 moles.
Molarity of HNO₃ = 15.55 M
Mass of water = Total mass of nitric acid solution - mass of nitric acid
= 1420 - 979.8
= 440.2 g
So we see that 440.2 g of water contains 15.55 moles of HNO₃
Molality is defined as number of moles of HNO₃ present per 1000 g of water.
Molality of HNO₃ = 
= 35.325 molal
Answer: The molar concentration of oxygen gas in water is
.
Explanation:
Partial pressure of the
gas = 685 torr = 0.8905 bar
1 torr = 0.0013 bar
According Henry's law:

Value of Henry's constant of oxygen gas at 20 °C in water = 34860 bar


Let the number of moles of
gas in 1 liter water be n.
1 Liter water = 1000 g of water
Moles of water in 1 L 




Molar concentration of oxygen gas in 1 L of water:

The molar concentration of oxygen gas in water is
.