Answer:
(c.) as the force of Earth's gravity on an object increases, the object's mass increases
Explanation:
Based on newton's law of gravitation "every particle of matter in the universe attracts every other particle with a force that is directly proportional to the product of the masses of the particles and inversely proportional to the square of the distance between them".
It is mathematically expressed as:
F = 
F is the gravitational force on either particle
m₁ and m₂ are the masses
r is the distance between particles
G is the universal gravitation constant.
From this expression, we see that the force of earth's gravity is directly proportional to mass.
I believe your answer is: What is the enthalpy of formation of magnesium oxide?
Hope this helps! :)
Answer: 15.1 grams
Given reaction:
Na2CO3 + Ca(OH)2 → 2NaOH + CaCO3
Mass of Na2CO3 = 20.0 g
Molar mass of Na2CO3 = 105.985 g/mol
# moles of Na2CO3 = 20/105.985 = 0.1887 moles
Based on the reaction stoichiometry: 1 mole of Na2CO3 produces 2 moles of NaOH
# moles of NaOH produced = 0.1887*2 = 0.3774 moles
Molar mass of NaOH = 22.989 + 15.999 + 1.008 = 39.996 g/mol
Mass of NaOH produced = 0.3774*39.996 = 15.09 grams
Explanation: