Answer:
Copper (II) sulfate
Explanation:
Given reaction is
2Al(s) + 3CuSO4(aq) → Al2(SO4)3(aq) + 3Cu(s)
Amount of aluminum = 1·25 g
Amount of copper (II) sulfate = 3·28 g
Atomic weight of Al = 26 g
Molecular weight of CuSO4 ≈ 159·5
Number of moles of Al = 1·25 ÷ 26 = 0·048
Number of moles of CuSO4 = 3·28 ÷ 159·5 = 0·021
From the above balanced chemical equation for every 2 moles of aluminum, 3 moles of copper (ll) sulfate will be required
So for 1 mole of Al, 1·5 moles of copper (ll) sulfate will be required
For 0·048 moles of Al, 1.5 × 0·048 moles of copper (ll) sulfate will be required
∴ Number of moles of copper (ll) sulfate required = 0·072
But we have only 0·021 moles of copper (ll) sulfate
As copper (ll) sulfate is not there in required amount, the limiting reactant will be copper (ll) sulfate
∴ The limiting reactant is copper (ll) sulfate
Answer:
<em>D. One negative charge</em>
Explanation:
During the formation of a bond, if an atom gains an electron, after that it will be left with a negative charge compared to the atom before the bond is formed. This is because in these types of bonds, which are <em>ionic bonds</em>, there is a <em>transfer of electrons between atoms</em>, there will be one or more atoms that yield electrons that will be captured by another and other atoms that gain them, and the difference of charges produced by this transfer of electrons, will cause the union to occur due to the attraction between electrostatic forces.
If you have a neutral atom before joining, and it gains an electron to form a bond,<em> it will have one electron more than its initial state</em> (in the initial state, the number of protons and electrons is the same, because the atoms they are electrically neutral), so having an extra electron will make it have a negative charge, since there will be a difference between the number of protons and electrons that the atom possesses. <em>This is why the correct answer is D.
</em>
In the case of <em>response A and B</em>, <em>the atom could only remain positively charged if it loses electrons</em>, but as in this case it wins, <em>they are not correct</em>.
<em>The answer C is also not correct</em> because only one electron wins, so that it is left with two negative charges, <em>it should gain two electrons during the bond formation.</em>
Answer: -
6
Explanation: -
The given unbalanced chemical equation is As + NaOH -- > Na3AsO3 + H2
We see there 3 sodium on the right side from Na3AsO3.
But there are only 1 sodium on the left from NaOH.
So we multiply NaOH by 3.
As + 3 NaOH -- > Na3AsO3 + H2
Now we see the number of Hydrogen on the left is 3.
But the number of hydrogens is 2 on the left.
So, we multiply to get both sides 6 hydrogen.
As + 6NaOH -- > Na3AsO3 + 3 H2
Rebalancing for Na,
As + 6NaOH -- > 2Na3AsO3 + 3 H2.
Finally balancing As,
2 As + 6 NaOH -- > 2Na3AsO3 + 3H2
The coefficient of the NaOH molecule in the balanced reaction is thus 6
Answer:
1) acetylide
2) enol
3) aldehydes
4) tautomers
5) alkynes
6) Hydroboration
7) Keto
8) methyl ketones
Explanation:
Acetylide anions (R-C≡C^-) is a strong nucleophile. Being a strong nucleophile, we can use it to open up an epoxide ring by SN2 mechanism. The attack of the acetylide ion occurs from the backside of the epoxide ring. It must attack at the less substituted side of the epoxide.
Oxomercuration of alkynes and hydroboration of alkynes are similar reactions in that they both yield carbonyl compounds that often exhibit keto-enol tautomerism.
The equilibrium position may lie towards the Keto form of the compound. Usually, if terminal alkynes are used, the product of the reaction is a methyl ketone.
<h3><u>Answer;</u></h3>
<u>= 5 M or 5 moles/liter</u>
<h3><u>Explanation;</u></h3>
At point E, 90 g of substances X are dissolved in 100 g of the solvent.
100g of the solvent is equal to 100 ml
Molarity is the number of moles of a substance in one liter of a solvent.
90 g of X are in 100 ml
But; the RFM of X = 180 g/l
Therefore; the moles of X in 90 g = 90/180
= 0.5 moles
Therefore;
0.5 moles of X are contained in 100 ml of the solvent;
Thus, molarity = 0.5 × 1000/100
=<u> 5 M or 5 moles/liter</u>
