Answer:
²³⁵₉₂U
Explanation:
The right symbol for the nuclei is ²³⁵₉₂U;
For this chemical element, the atom is represented by the symbol U;
To the superscript before the symbol is the mass number
The subscript before the symbol is the atomic number
Mass number is the number of protons and neutrons
Atomic number is the number of protons.
I will solve this question assuming the reaction equation look like this:
<span>MnO2 + 4 HCl ---> MnCl2 + Cl2 + 2 H2O.
</span>
For every one molecule of MnO2 used, there will be one molecule of Cl2 formed. If the molecular mass of MnO2 is 87g/mol and molecular mass of Cl2 is <span> 73.0 g/mol, the mass of MnO2 needed would be:
Cl mass/Cl molecular mass * MnO2 molecular mass=
25g/ (73g/mol) * (87g/mol) * 1/1= 29.8 grams</span>
(2) a base because they accept H+ ions. NH3 is the conjugate base of NH4+.
CuSO₄ + 2NaOH → Cu(OH)₂ + Na₂SO₄
M(CuSO₄)=159.61 g/mol
m(CuSO₄)=638.44 g
n(CuSO₄)=m(CuSO₄)/M(CuSO₄)
n(CuSO₄)=638.44/159.61= 4.00 mol
M(NaOH)=40.00 g/mol
m(NaOH)=240.0 g
n(NaOH)=m(NaOH)/M(NaOH)
n(NaOH)=240.0/40.00= 6.00 mol
on the reaction equation
CuSO₄ : NaOH = 1 : 2
in practice
CuSO₄ : NaOH = 4 : 6 = 1 : 1.5 ⇒ NaOH is the limiting reactant