Answer:
c
Explanation:
you don't think of particles as dense and less dense
dust particles containvenergy but won't release it unless acted upon a force
gas molecules move freely and collide with dust particles which is correct
Answer:
87.9%
Explanation:
Balanced Chemical Equation:
HCl + NaOH = NaCl + H2O
We are Given:
Mass of H2O = 9.17 g
Mass of HCl = 21.1 g
Mass of NaOH = 43.6 g
First, calculate the moles of both HCl and NaOH:
Moles of HCl: 21.1 g of HCl x 1 mole of HCl/36.46 g of HCl = 0.579 moles
Moles of NaOH: 43.6 g of NaOH x 1 mole of NaOH/40.00 g of NaOH = 1.09 moles
Here you calculate the mole of H2O from the moles of both HCl and NaOH using the balanced chemical equation:
Moles of H2O from the moles of HCl: 0.579 moles of HCl x 1 mole of H2O/1 mole of HCl = 0.579 moles
Moles of H2O from the moles of NaOH: 1.09 moles of HCl x 1 mole of H2O/1 mole of NaOH = 1.09 moles
From the calculations above, we can see that the limiting reagent is HCl because it produced the lower amount of moles of H2O. Therefore, we use 0.579 moles and NOT 1.09 moles to calculate the mass of H2O:
Mass of H2O: 0.579 moles of H2O x 18.02 g of H2O/1 mole of H2O = 10.43 g
% yield of H2O = actual yield/theoretical yield x 100= 9.17 g/10.43 g x 100 = 87.9%
Answer:
665 kJ
Explanation:
We assume that carbohydrates and protein each have 4 kilocalories per gram, and that fat has 9 kilocalories per gram. Then the number of kilocalories in the peanut butter is ...
4(6 +9) +9(11) = 159 . . . . kilocalories
Each kilocalorie translates to 4.184 kilojoules, so the total is ...
(159 kCal)(4.184 kJ/kCal) = 665.256 kJ
2 Tbsp of crunchy peanut butter contains about 665 kJ of energy.
