Density = Mass / Volume
V = 1.00 * 4.00 * 2.50 = 10 cm³
22.57 g/cm³ = Mass / 10 cm³
M = 22.57 g/cm³ * 10 cm³
M = 225.7 g
Answer: The mass of the block of osmium is 225.7 g.
<u>Answer:</u>
For 2: The correct answer is grams of solute per 100 grams of solvent.
For 3: The correct answer is supersaturated.
For 4: the correct answer is the solubility decreases.
<u>Explanation:</u>
Solubility is defined as the property which refers to the ability of the solute that can be dissolved in a solvent. It is defined as the number of grams of solute per 100 grams of solvent.
Unsaturated solution is defined as the solution in which amount of solute that is dissolved in the solvent is less.
Saturated solution is defined as the solution in which no more solute can be dissolved in the given amount of solvent.
Emulsion is defined as the dispersion of one liquid in another liquid in which it is not soluble.
Supersaturated solution is defined as the solution in which solvent contains more amount of solute than the required amount. These solutions help in the process of crystallization.
When a crystal is added to a <u>supersaturated solution</u>, more and more particles come out of the solution and this process is known as crystallization.
According to the Henry's Law
The solubility of the gas in a liquid is directly proportional to the partial pressure of the gas.

With increase in the partial pressure, the solubility of the gas in liquid also increases and vice-versa.
Hence, the correct answer is the solubility decreases.
Today they will practice measuring different liquids. They will use a container called a graduated cylinder to measure liquids. Graduated cylinders have numbers on the side that help you determine the volume. Volume is measured in units called liters or fractions of liters called milliliters (ml).
Answer : The number of moles of
produced will be, 0.241 moles.
Solution : Given,
Mass of Fe = 27.0 g
Molar mass of
= 56 g/mole
First we have to calculate the moles of
.

Now we have to calculate the moles of 
The balanced chemical reaction is,

From the reaction, we conclude that
As, 4 mole of
react to give 2 mole of 
So, 0.482 moles of
react to give
moles of 
Thus, the number of moles of
produced will be, 0.241 moles.
Answer: (B) Pressure is due to the collisions of the gas particles with the walls of the container.
Option B helps to explain the factor behind gas collision under high pressure.
Explanation: Kinetic molecular theory explains the behaviour and movement of gas particles when they are in motion. It states that gas particles are always in continuous motion and are perfectly elastic in nature.
Kinetic molecular theory can be explained using both Boyle's law and Charles's law.
•Few Assumptions of Kinetic Molecular Theory.
1. Gas particles are always in motion and they collide with the walls of their container.
2. The space occupied by a gas particles is negligible in comparison to the volume of the gas