Explanation:
It is the heat required to change a gram of substance from a liquid to a gas.
Properties of matter can be broadly classified into two categories:
Physical properties which usually involve a change in the state of matter and Chemical properties which involve a change in the chemical composition of matter.
Now, physical properties can be further classified as:
Extensive: these depend on the amount of the substance, eg: mass, volume
Intensive: these do not depend on the amount of the substance eg: density, color, melting point, boiling point
Here we are given a 5.0 g and 1 cm3 silver cube :
Therefore:
Extensive properties are-
1) Mass of silver = 5.0 g
2) Volume of silver = 1 cm3
Intensive properties are:
1) Density of silver = mass/volume = 5.0 g/ 1 cm3 = 5.0 g/cm3
2) Melting point of silver = 962 C
3) Color = white/gray
Answer:
a) The relationship at equivalence is that 1 mole of phosphoric acid will need three moles of sodium hydroxide.
b) 0.0035 mole
c) 0.166 M
Explanation:
Phosphoric acid is tripotic because it has 3 acidic hydrogen atom surrounding it.
The equation of the reaction is expressed as:

1 mole 3 mole
The relationship at equivalence is that 1 mole of phosphoric acid will need three moles of sodium hydroxide.
b) if 10.00 mL of a phosphoric acid solution required the addition of 17.50 mL of a 0.200 M NaOH(aq) to reach the endpoint; Then the molarity of the solution is calculated as follows

10 ml 17.50 ml
(x) M 0.200 M
Molarity = 
= 0.0035 mole
c) What was the molar concentration of phosphoric acid in the original stock solution?
By stoichiometry, converting moles of NaOH to H₃PO₄; we have
= 
= 0.00166 mole of H₃PO₄
Using the molarity equation to determine the molar concentration of phosphoric acid in the original stock solution; we have:
Molar Concentration = 
Molar Concentration = 
Molar Concentration = 0.166 M
∴ the molar concentration of phosphoric acid in the original stock solution = 0.166 M
Answer:
The elements in Group 2 (beryllium, magnesium, calcium, strontium, barium, and radium) are called the alkaline earth metals (see Figure below). These elements have two valence electrons, both of which reside in the outermost s sublevel. The general electron configuration of all alkaline earth metals is ns