From the reaction between Cu and HNO₃, the formed gas is NO₂ instead of NO₃. Hence the correct balanced equation would be,
Cu(s) + 4HNO₃(aq) → Cu(NO₃)₂(aq) + 2NO₂(g) + 2H₂O<span>(l)
Here, Cu goes to </span>Cu(NO₃)₂ by changing its oxidation number from 0 to +2 while NO₃⁻ goes to NO₂ by reducing its oxidation state from +5 to +4 . Hence Cu is oxidized by HNO₃ in the reaction.
The one that starts with c that is also the one that is anwser number c which is a
We are told that the concentration of sodium hypochlorite is 4.0% (w/v). To calculate the molarity of the sodium hypochlorite solution, let us consider a sample volume of 0.1 liter. Since we are given a w/v (Percent of weight of solution in the total volume of solution) value, it means that there are 4 <span>grams of sodium hypochlorite per 100 mL of solution (0.1 liter). Molarity is measured in moles per liter. So we'll just convert the given 4 grams to moles using the molar mass.
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4 grams</span>sodium hypochlorite * (1 mol sodium hypochlorite/ 74.44 g sodium hypochlorite) = 0.054 moles sodium hypochlorite
So we have 0.054 moles sodium hypochlorite / 0.1 L solution
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Thus the molarity is 0.53 mol/L or just 0.53 M.
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Answer:
c. Energy from the liquid is exhausted into the atmosphere outside the freezer
Explanation:
Energy from the liquid is exhausted into the atmosphere outside the freezer.
a. is wrong. If the energy remained inside the freezer, the warm liquid would cool down and the inside of the freezer would warm up.
b. is wrong. The freezer removes energy from the liquid.