I’m not 100% sure but I think it’s 1098
Answer:
star
Explanation:
stars are composed of 92.1 percent hydrogen and 7.8 percent helium.
Answer:
The questions are incomplete
Explanation:
(b) This question is incomplete. However to calculate the number of moles of CuSO₄ present in the impure sample. The formula below can be used;
number of moles = mass of CuSO₄ present in the impure sample ÷ molar mass of CuSO₄
(c) This question is also incomplete. However, to calculate the mass percentage of CuSO₄ present in the impure sample of CuSO₄, the formula below can be used.
Mass percentage of CuSO₄ =
mass of CuSO₄ present in the impure sample/mass of impure CuSO₄ × 100
Thus, the mass of the impure sample must be measured also since the actual mass of the CuSO₄ present in the impure sample must have been measured before calculating the number of moles.
Cr2(SO4)3(aq) + 3(NH4)2CO3(aq) → 3(NH4)2SO4(aq) + Cr2(CO3)3(s)
<span>Ionic: 2Cr+3 + 3SO4^-2 + 6NH4+ + 3CO3^-2 ----> 6NH4+ + 3SO4^-2 + Cr2(CO3)3 (spectator ions are NH4+, SO4^-2) </span>
<span>Net Ionic: 2Cr^+3(aq) + 3CO3^-2(aq) -------> Cr2(CO3)3(s) </span>
Ammonia is formed by a reaction between hydrogen and nitrogen as shown by the equation below.
N2(g) + 3H2(g) = 2NH3(g)
1 mole of ammonia contains 17 g
Therefore 10.78 g of ammonia are equivalent to 10.78/17 = 0.6341 moles
The mole ratio of hydrogen to ammonia is 3 : 2
Therefore, moles of hydrogen used will be 0.6341 × 3/2 = 0.9512 moles
1 mole of hydrogen is equivalent to 2 g
Thus, the mas of hydrogen will be 0.9512 moles × 2 = 1.9023 g
