What mass of ice at 0°C can be melted by the addition of 1670 joules of heat?
When the temperature is decreased on the following system at equilibrium:
2 HCl(aq) + Mg(s) <--> MgCl2(aq) + H2(g) + heat
a. In order to restore equilibrium, the reaction shifts left, toward reactants
b.No change occurs
c. In order to restore equilibrium, the reaction shifts right, toward products
1670J = mass ice x heat fusion.
The system shifts to undo what we've done. How can it do that? Obviously, if we decrease T the system will try to increase T. Which way will it shift to do that?
What mass of ice at 0°C can be melted by the addition of 1670 joules of heat?
Well, if the temperature is decreased, it means it's getting colder in here! Brrr! Now, let's take a look at the reaction. When the temperature decreases, according to Le Chatelier's principle, the system will try to counteract the change. In this case, it's trying to warm things up a bit, just like a cozy fireplace on a chilly night.
Since heat is considered a product in this reaction, decreasing the temperature will cause the reaction to shift to the right, towards the products, in an attempt to replace the lost heat. So, the answer is c. In order to restore equilibrium, the reaction will shift right, towards products. Keep warm and carry on, my friend!
To calculate the mass of ice that can be melted by the addition of 1670 joules of heat, we can use the specific heat capacity of ice.
The specific heat capacity of ice is 2.09 J/g°C.
We know that the heat required to melt a substance can be calculated using the formula:
heat = mass * specific heat capacity * change in temperature
Since the ice is at 0°C and we want to melt it completely, the change in temperature is 0°C.
Therefore, we can rearrange the formula to solve for mass:
mass = heat / (specific heat capacity * change in temperature)
Substituting the given values:
mass = 1670 J / (2.09 J/g°C * 0°C)
mass = 1670 J / 0 J/g
Since the numerator is a non-zero value and the denominator is zero, we cannot perform this calculation. The mass of ice that can be melted cannot be determined with the given information.
Regarding the equilibrium reaction:
In this reaction, 2 moles of HCl reacts with 1 mole of Mg to form 1 mole of MgCl2 and 1 mole of H2 gas. The reaction also gives off heat.
To determine the shift in equilibrium when the temperature is decreased, we need to consider Le Chatelier's principle.
According to Le Chatelier's principle, a decrease in temperature will cause the reaction to shift in the exothermic direction (right) to restore equilibrium. This means the reaction will shift toward the products (MgCl2 and H2) to counteract the decrease in temperature.
Therefore, the correct answer is:
c. In order to restore equilibrium, the reaction shifts right, toward products.
To calculate the mass of ice that can be melted by the addition of heat, we need to use the concept of specific heat and phase changes. The specific heat capacity of ice is 2.09 J/g°C, and the heat required to melt ice at 0°C is called the heat of fusion, which is 334 J/g. Here's how you can get the answer:
1. Calculate the heat required to raise the temperature of the ice from 0°C to its melting point (also 0°C):
- The specific heat capacity of ice is 2.09 J/g°C.
- The initial temperature of the ice is 0°C.
- The final temperature of the ice is its melting point, which is also 0°C.
- The formula for calculating heat is Q = m * c * ΔT, where Q is the heat, m is the mass, c is the specific heat capacity, and ΔT is the change in temperature.
- Since ΔT is 0 (0°C - 0°C = 0), the heat required to raise the temperature is 0 J.
2. Calculate the heat required to melt the ice at its melting point:
- The heat of fusion for ice is 334 J/g.
- The formula for calculating heat is Q = m * Hf, where Q is the heat, m is the mass, and Hf is the heat of fusion.
- Rearranging the formula, we get m = Q / Hf.
- Given that Q = 1670 J and Hf = 334 J/g, we can substitute these values into the formula: m = 1670 J / 334 J/g = 5 g.
Therefore, 5 grams of ice at 0°C can be melted by the addition of 1670 joules of heat.
Regarding the equilibrium shift in the given chemical reaction:
The reaction 2 HCl(aq) + Mg(s) ⇌ MgCl2(aq) + H2(g) + heat is an exothermic reaction because heat is released as a product. When the temperature is decreased, according to Le Chatelier's principle:
a. In order to restore equilibrium, the reaction shifts left, toward reactants.
- When the temperature is decreased, the system tries to compensate for the loss of heat by shifting the reaction in the direction that produces more heat. In this case, the reactant side has more heat production.