The atom that is made up of two protons is He. The number of neutrons is also two. The number of electrons matters in the charge. So to make 10 electrons, we add 8 more. hence, 4/2 He 8-.
N= m/v n=0.077/.200 = 0.385
Answer:
0.641 moles of ethane
Explanation:
Based on the equation:
C2H6(g) + 7/2O2(g) → 2CO2(g) + 3H2O(l)
We can determine ΔH of reaction using Hess's law. For this equation:
<em>Hess's law: ΔH products - ΔH reactants</em>
ΔH = {2ΔHCO2 + 3ΔHH2O} - {ΔHC2H6}
<em>Pure monoatomic substances have a ΔH = 0kJ/mol; ΔHO2 = 0kJ/mol</em>
<em />
ΔH = {2*-393.5kJ/mol + 3*-285.8kJ/mol} - {-84.7kJ/mol}
ΔH = -1559.7kJ/mol
That means when 1 mole of ethane is in combustion there are released 1559.7kJ of heat. To produce 1.00x10³kJ there are needed:
1.00x10³kJ * (1mole ethane / 1559.7kJ) =
<h3>0.641 moles of ethane</h3>
Answer:
Energy from the chemical bonds of the reactants is released to the surrounding.
Explanation:
Lead(II) phosphate is an ionic compound with chemical formula Pb3(PO4)2. Lead(II) phosphate is a long-lived electronically neutral reagent chemical.[1] Despite limited tests on humans, it has been identified as a carcinogen based on tests on animals conducted by the EPA.[2] Lead(II) phosphate appears as hexagonal, colorless crystals or as a white powder. Lead(II) phosphate is insoluble in water and alcohol but soluble in Nitric acid (HNO3) and has fixed alkali hydroxides. When lead(II) phosphate is heated for decomposition it emits very toxic fumes containing Lead (Pb) and POx.[3]
