Answer:
D. Gases were released to the atmosphere
Explanation:
In accordance to the law of conservation of mass, the total amount of reactants must equate the total amount of products at the end of the reaction because matter can not be lost or created. However, certain changes like gas evolution, formation of precipitate etc. indicates the occurrence of a chemical reaction.
In a chemical reaction, the total mass of the product(s) would be less than the total weight of the reactant(s) because GASES, which constituted part of the mass of the reaction, WERE RELEASED INTO THE ATMOSPHERE. However, if the mass of the gas released can be accounted for, the amount of reactants and products must balance.
Answer:
B. Decreasing the pressure applied to the gas molecules
Explanation:
According to Boyle's Law, the pressure of the gas is inversely proportional to the volume of the gas. So, the option B is correctly implied to it.
Other values such as Temperature, Number of molecules are inversely proportional to the volume of the gas.
Size of the gas molecules is negligible as compared to volume.
Answer:
Explanation:
Molarity refers to a measure of concentration.
Molarity = moles of solute/Litres of solution
Molarity refers to number of moles of solute present in this solution.
In order to find a solution's molarity, use value for the number of moles of solute and the total volume of the solution expressed in liters
As molarity of 2.3 mol of Kl is dissolved in 0.5 L of water,
Molarity = 
Answer:
Only one—(i), or (ii), or (iii)—increases the reaction rate.
Explanation:
<em>Which of the following changes always leads to an increase in the rate constant for a reaction?</em>
- <em>Decreasing the temperature. </em>NO. A lower temperature leads to a slower reaction because the molecules have less energy to react.
- <em>Decreasing the activation energy</em>. YES. According to the Arrhenius equation, the lower the activation energy, the higher the rate constant.
- <em>Making the value of ΔE more negative</em>. NO. A more negative ΔE means a reaction is more spontaneous but not faster.
