Answer:
14.61 g NaCl
Explanation:
Molarity = moles / volume of solution (litres)
0.500 = moles / 0.500 L
moles = 0.25
Molar mass of NaCl is 58.44 g NaCl /1 mol NaCl.
0.25 moles NaCl x 58.44 g NaCl /1 mol NaCl
= 14.61 g NaCl
Please provide more of the question so I am able to answer, but I do know that H20 has 0 calories.
Answer is: 315,29 grams of copper ore.
m(<span>chalcopyrite) = ?
</span>ω(CuFeS₂) = 55,0 % = 0,55.
<span>m(Cu) = 60,0 g.
mass percentage of copper in </span>CuFeS₂:
ω(Cu) = Ar(Cu) ÷ Mr(CuFeS₂).
ω(Cu) = 63,55 ÷ 183,4.
ω(Cu) = 0,346 = 34,6 %.
mass percentage of copper in chalcopyrite:
ω(Cu) : ω₁(Cu) = 100% : ω(CuFeS₂).
ω₁(Cu) = 19,03 % = 0,1903.
m(chalcopyrite) = 60,0 g ÷ 0,1903.
m(chalcopyrite) = 315,29 g.
Answer: 873 kJ of energy will be required to break two moles of hydrogen gas.
Above chemical equation shows that two moles of hydrogen gas is reacting with one mole of oxygen gas to give two mole of water molecule.
Bond energy of H-H = 436kJ
According to reaction we have two moles hydrogen,so energy required to break the
H-H bond in two moles of hydrogen gas will be:
= 872kJ
872kJ of energy will be required to break H-H bond in two moles of hydrogen gas.
The answer should be A, has more energy than it does in the ground state. De-excitation is removing electrons, so excitation would be adding more in to make it more stable. The ground state is what is considerd stable.
ANSWER: A
