<u>Answer:</u> The number of moles of calcium metal required is 2.0 moles.
<u>Explanation:</u>
We are given:
Moles of water reacted = 4.0 moles
The given chemical reaction follows:
By Stoichiometry of the reaction:
2 moles of water is reacted with 1 mole of calcium metal
So, 4.0 moles of water will react with = 
of calcium metal
Hence, the number of moles of calcium metal required is 2.0 moles.
Answer : 17.12 g
Explanation:
= elevation in boiling point
= boiling point elevation constant
m= molality
given 
Molar mass of solute = 46.0 
Weight of the solvent = 150.0 g = 0.15 kg
Putting in the values
x = 17.12 g
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Iconic +covalent is the answer to this
Answer:
ELEMENTS
COMPOUNDS
Elements are made up of one kind of atoms.
Compounds are made up of two or more kinds of atoms.
Elements cannot be broken down into simpler substances by any physical or chemical method.
Compounds can be broken down into simpler substances by chemical methods.
Elements have their own set of properties.
Properties of a compound differ from those of their elements.
Examples: Hydrogen, Oxygen
Examples: Water, Sodium chloride
