48.1 grams.
<h3>Explanation</h3>
How many moles of the reaction is needed to provide that 335 kJ of heat?
- ΔH = -824.2 kJ / mol according to the equation. In other words, each mole of the reaction releases 824.2 kJ of heat. (The value of ΔH is negative, which means that the reaction produces energy.)
- 335 / 842.2 = 0.4307 mol. It takes 0.4307 moles of the reaction <em>shown in the equation</em> to produce all the 335 kJ of heat.
How many moles of iron, Fe in 0.4307 moles of the reaction?
- The coefficient in front of Fe in the equation is two. As a result, each mole of this reaction would consume two moles of Fe. The 0.4307 moles of the reaction will consume 2 × 0.4307 = 0.861 moles of Fe to produce 335 kJ of heat.
What's the mass of 0.8614 moles of iron, Fe?
- Refer to a modern periodic table, the relative atomic mass of iron Fe is 55.85. As a result, the mass of one mole of iron Fe is 55.85 grams.
- 0.861 × 55.85 = 48.1 grams. Therefore, it takes 48.1 grams of iron to provide 335 kJ of heat through this reaction.
The student is incorrect. Although the amount of copper sulfate dissolved has increased in the new solution, we also have to account for the fact that the amount of water has also increased.
To see whether or not the new solution is more concentrated, we can compare the grams of copper sulfate in each solution to the amount of water in each solution.
Solution A: ![\frac{5g}{50 mL} = .1 g/mL](https://tex.z-dn.net/?f=%5Cfrac%7B5g%7D%7B50%20mL%7D%20%3D%20.1%20g%2FmL)
Solution B: ![\frac{10g}{100mL} = .1 g/mL](https://tex.z-dn.net/?f=%5Cfrac%7B10g%7D%7B100mL%7D%20%3D%20.1%20g%2FmL)
Solution A + Solution B: ![\frac{15g}{150mL} =.1g/mL](https://tex.z-dn.net/?f=%5Cfrac%7B15g%7D%7B150mL%7D%20%3D.1g%2FmL)
You'll notice that the concentration for all these solutions is .1 g copper sulfate/1mL
This means that the new solution (A+B) is not more concentrated -- the increase of dissolved copper sulfate was diluted by the additional increase of water, such that the concentration of the new solution was not greater than its component solutions (A and B).
Answer:
A
Explanation:
A man has to give 23 and women has to also give 23.