Answer:
+1, lose, 1, 4s, 4s and 3d
Explanation:
<em>An element with the valence electron configuration 4s¹ would form a monatomic ion with a charge of </em><em>+1</em><em>. In order to form this ion, the element will </em><em>lose</em><em> </em><em>1 </em><em>electron from the </em><em>4s </em><em>subshell.</em>
The corresponding oxidation reaction is:
K ⇒ K¹⁺ + 1 e⁻
[Ar] 4s¹ ⇒ [Ar]
<em>If an element with the valence configuration 4s² 3d⁶ loses 3 electrons, these electrons would be removed from the </em><em>4s and 3d</em><em> subshell(s).</em>
The corresponding oxidation reaction is:
Fe ⇒ Fe³⁺ + 3 e⁻
[Ar] 4s² 3d⁶ ⇒ [Ar] 4s⁰ 3d⁵
<span>1.4 moles of aluminium metal is exposed to 1.35 mol of oxygen
Theoretical yield=0.007 mol
calculate % yield
% yield= actual yield/theoretical yield*100
% yield= 0.938/0.700*100
% yield= 13.4% yield</span>
Answer:
A - 3
B - 6
Explanation:
The valency of hydrogen atom is +1
The valancy of an atom of other element combining with the hydrogen atom can be determined from the number of associated hydrogen.
when H combines with A, three atoms of hydrogen are used. Thus the valency of element A is -3
Now B combines with two molecules of A whose valency is -3
The valency of B would be twice the valency of element A i.e 6
if hydrogen combines with B, then the compound formed will be BH6
Answer:
4.5 kilograms of silicon dioxide is required to produce 3.00 kg of SiC.
Explanation:
The balanced equation for the reaction between silicon dioxide and carbon at high temperature is given as:
1 mole silicon dioxide reacts with 3 moles of carbon to give 1 moles of silicon carbide and 2 moles of carbon monoxide.
Mass of SiC = 3.00kg = 3000.00 g
1 kg = 1000 g
Molecular mass of SiC = 40 g/mol
Moles of SiC = 
According to reaction, 1 mole of SiC is produced from 1 mole of silicon dioxide.
Then 75 moles of SiC will be produce from:
of silicon dioxide.
mass of 75 moles of silicon dioxde:
4.5 kilograms of silicon dioxide is required to produce 3.00 kg of SiC.
Answer:
- (0.1 mol NaH₂PO₄ + 0.1 mol Na₂HPO₄)
Explanation:
A buffer solution is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or weak base and its conjugate acid.
Also, a buffer solution is a solution which resists changes in pH when acid or alkali is added to it.
- (0.1 mol NaH₂PO₄ + 0.1 mol Na₂HPO₄) when dissolved in 1 L H₂O will produce a buffer because NaH₂PO₄ is considered as weak acid while Na₂HPO₄ is its conjugate base. 2.
- (0.1 mol H₃O⁺ + 0.1 mol Cl⁻) is not a mixture of a weak acid and its conjugate base, or weak base and its conjugate acid.
- (0.1 mol HCl + 0.1 mol NaoH) HCL is a strong acid and NaOH is a strong base so it will not form a buffer when dissolved in water.
- (0.1 mol H₃O⁺ + 0.1 OH⁻) is not a mixture of a weak acid and its conjugate base, or weak base and its conjugate acid
- (0.1 mol NaCl+ 0.1 mol KCl) NaCL and KCL are salts so it will not form a buffer when dissolved in water.
So the right choice is
- (0.1 mol NaH₂PO₄ + 0.1 mol Na₂HPO₄)
