Answer:
The mass of copper = 208.26 grams.
Explanation:
Density = mass / volume
8.9 = mass / 23.4
mass = 8.9 * 23.4
= 208.26 grams.
Answer:

Explanation:
Hello!
In this case, since we can see that the heat released by the combustion of the mayonnaise is absorbed by the bomb calorimeter and water, we can set up the following equation:

Whereas q for mayonnaise stands for the heat due to its usage; thus, we plug in to obtain:

Now, if 10.0 g are eaten, the energy provided by it turns out:

And we need that value in dietary calories, 1 kcal:

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Answer:
About 2 liters
Explanation:
Since 1 gallon equals 3.785 liters, you figure out how many liters per week she uses by 3.785 x 0.75 which is 2.83875. Then divide that by 7 which is 0.405535 liters per day. Then multiply that by 5 days which is 2.027 liters in 5 days.
The answer is 10.81 g of boron.