Joshua saw the rising batter form the cake in the oven.
He saw that because of the reaction of baking soda/powder with the liquid in the batter.
Answer:
Percentage mass of copper in the sample = 32%
Explanation:
Equation of the reaction producing Cu(NO₃) is given below:
Cu(s)+ 4HNO₃(aq) ---> Cu(NO₃)(aq) + 2NO₂(g) + 2H₂O(l)
From the equation of reaction, 1 mole of Cu(NO₃) is produced from 1 mole of copper. Therefore, 0.010 moles of Cu(NO₃) will be produced from 0.010 mole of copper.
Molar mass of copper = 64 g/mol
mass of copper = number of moles * molar mass
mass of copper = 0.01 mol * 64 g/mol = 0.64 g
Percentage by mass of copper in the 2.00 g sample = (0.64/2.00) * 100%
Percentage mass of copper in the sample = 32%
Im pretty sure its D. I would wait for others though.
Butane is 2, and carbon dioxide is 8. which makes the mole ratio of butane to carbon dioxide 2:8, which simplifies to 1:4.
The standard enthalpy of reaction should be negative.
<h3>What is enthalpy?</h3>
A thermodynamic quantity equivalent to the total heat content of a system. It is equal to the internal energy of the system plus the product of pressure and volume.
Inside the heat pack are two chemicals that get mixed when you smush them together. As they mix, some weak bonds are broken, which takes a little bit of energy. But new, stronger bonds form which release energy. Releasing that energy causes the surroundings to heat up.
Hence, option B is correct.
Learn more about enthalpy here:
brainly.com/question/13775366
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