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
I am pretty sure the answer is B but correct me if I'm wrong hope this helps.
Answer:
Intrusive and Extrusive igneous rocks.
Explanation:
Igneous rocks are defined as those rocks that are formed when magma undergoes the process of crystallization and solidification at or below the earth's surface. For example, Granite, Rhyolite, Gabbro and Diorite.
The igneous rocks are of two different types, namely-
- Intrusive igneous rocks- This type of igneous rocks are formed when the magma crystallizes below or within the earth's crust. For example, Granite.
- Extrusive igneous rocks- This type of igneous rocks are formed when the magma crystallizes and solidifies at the surface of the earth. For example, Basalt.
Weight of sodium thiosulfate = 76.148 - 8.2
= 67.948 g.
Concentration of the solution = 67.948 / 172.7
= 0.393 g / mL. to the nearest thousandth . (answer).
