Answer:True
Explanation:
Water is said to be hard when it contains calcium ions or magnesium ions dissolved in it. These ions are able to react with soap in such a way that the soap is prevented from forming lather with the water. Hard water occurs when water passes over calcium or magnesium bearing minerals and dissolves some of it. Hardness due to the presence of calcium ions can easily be removed by boiling the water.
Answer:
Molecular weight of the compound = 372.13 g/mol
Explanation:
Depression in freezing point is related with molality of the solution as:

Where,
= Depression in freezing point
= Molal depression constant
m = Molality


m = 0.26
Molality = 
Mass of solvent (toluene) = 15.0 g = 0.015 kg

Moles of compound = 0.015 × 0.26 = 0.00389 mol

Mass of the compound = 1.450 g

Molecular weight = 
Answer: for an object or gas or liquid to float in another there must be a difference in density
Explanation:
Helium has a density of 0.18 kg/m³ and air has a density of 1.29 kg/m^³. If a balloon is filled with helium it will float in air due to density differences
Archimedes' principle states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces
Answer:
V₂ = 236.84 mL
Explanation:
The relation between pressure and volume is inverse.
We can write it as follows :

We have,
P₁ = 360 torrs, V₁ = 750 mL, P₂ = 1.5 atm = 1140 torr.
So,

So, the new volume of the gas is 236.84 mL.
Answer:
<h2>1093750 J</h2>
Explanation:
The kinetic energy of an object can be found by using the formula

v is the velocity
m is the mass
From the question we have

We have the final answer as
<h3>1,093,750 J</h3>
Hope this helps you