I need help with question 6 Ocean water contains about 4.2 g of salt (which you
ID: 228068 • Letter: I
Question
I need help with question 6
Ocean water contains about 4.2 g of salt (which you can assume to be NaCI) for every 125 g of water. Using AT -kim and using 1.86 °C+kg/mol for the cryoscopic constant, estimate the freezing point of ocean water. 5. 6. As you know from your chemical reactions lab, magnesium metal will react with a 0.1 M solution of hydrochloric acid to produce hydrogen gas: Mg(s) + 2HCl(aq) MgCl2(aq) + H2(g) What effect will each change have on the rate of this reaction (faster, slower, or no effect)? a. Adding more 0.1 M HCl solution b. Diluting the HCl solution by adding water c. Cutting the magnesium metal into smaller pieces d. Cooling the 0.1 M HCl solution in a refrigerator before the reactionExplanation / Answer
6a Ans. In this reaction, Mg is in solid form and therefore, it reacts with 0.1M HCl only on its surface. So, we can say Mg solid is the limiting reactant.
Increasing the volume of 0.1 M HCl solution does not increase the reaction rate because the HCl solution is not the limiting reactant. Addition of more 0.1M HCl solution does not have effect on the reaction rate.
6b Ans. Diluting the 0.1 M HCl with water decreases the concentration of HCl. The reaction rate depends on the concentration of HCl solution. So adding water to HCl solution decreases the rate of the reaction.
6c Ans. Cutting the Mg metal into smaller pieces will increase the rate of the reaction. This is because cutting the MG metal into smaller pieces increase the surface area of Mg resulting in more reaction taking place thereby increasing the reaction rate.
6d Ans. Cooling the 0.1 M HCl before the reaction will decrease the rate of the reaction because rate of reaction depends on the temperature of the reaction. Cooling the HCl solution before use decreases the reaction temperature thereby lowering the reaction rate.