Answer:
C: The atoms involved in the chemical reaction
Explanation:
In a chemical reaction, when we balance it up, the number of moles or atoms on the left side must equal that on the right hand side. And thus, the mass is found in the atoms involved in such chemical reaction.
Answer:
D. The amount of heat required to increase the temperature of 1 g of a substance by 1 °C.
Explanation:
Specific heat is defined as the amount of heat needed to raise a unit of mass of a compound by one degree on the temperature scale.
The gram is constituted as a unit of mass, and the degree Celsius as a unit of temperature, therefore, the specific heat can be defined as the amount of heat required to increase the temperature of 1 g of a substance by 1 °C.
Answer: C. no new substances
are formed<span>
</span><span>
<span>In the
physical change of matter, there is no new substance that is formed. It is only
the appearance of the matter that is being changed and not its chemical
composition. Cutting, tearing and grinding are only some of the examples that
exhibit physical change. </span></span>
Answer:
molality of sodium ions is 1.473 m
Explanation:
Molarity is moles of solute per litre of solution
Molality is moles of solute per kg of solvent.
The volume of solution = 1 L
The mass of solution = volume X density = 1000mL X 1.43 = 1430 grams
The mass of solute = moles X molar mass of sodium phosphate = 0.65X164
mass of solute = 106.6 grams
the mass of solvent = 1430 - 106.6 = 1323.4 grams = 1.3234 Kg
the molality = 
Thus molality of sodium phosphate is 0.491 m
Each sodium phosphate of molecule will give three sodium ions.
Thus molality of sodium ions = 3 X 0.491 = 1.473 m
