use the table on the right to calculate each required quantity. remember: $q = ndelta h$. the quantity of…

use the table on the right to calculate each required quantity. remember: $q = ndelta h$. the quantity of heat required to melt 175 g cu is kj. the substance that releases 21.2 kj of energy when 1.42 mol of it freezes is.

use the table on the right to calculate each required quantity. remember: $q = ndelta h$. the quantity of heat required to melt 175 g cu is kj. the substance that releases 21.2 kj of energy when 1.42 mol of it freezes is.

Answer

Explanation:

Step1: Calculate the number of moles of Cu

The molar mass of Cu is 63.55 g/mol. The number of moles $n$ of Cu is calculated by $n=\frac{m}{M}$, where $m = 175$ g and $M=63.55$ g/mol. So $n=\frac{175}{63.55}\approx2.754$ mol.

Step2: Calculate the heat required to melt Cu

We know that $\Delta H_{fus}$ for Cu is 13.0 kJ/mol and $q = n\Delta H$. Substituting $n = 2.754$ mol and $\Delta H=13.0$ kJ/mol into the formula, we get $q=2.754\times13.0 = 35.8$ kJ.

Step3: Calculate the $\Delta H_{fus}$ for the second - part

We know that $q = n\Delta H$. Given $q = 21.2$ kJ and $n = 1.42$ mol, then $\Delta H=\frac{q}{n}=\frac{21.2}{1.42}\approx14.9$ kJ/mol. From the table, the substance with $\Delta H_{fus}\approx14.9$ kJ/mol is Fe.

Answer:

35.8 Fe