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3 years ago

An element belongs to the period 4 and group VB, write down its electron configuration?

Chemistry

1 answer:

Serjik [45]3 years ago

4 0

Answer:

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A 0.964 gram sample of a mixture of sodium formate and sodium chloride is analyzed by adding sulfuric acid. The equation for the

frosja888 [35]

Answer: 67.8 %.

Explanation:

Okay, let us delve right into the solution to the question;

The balanced chemical reaction is given by the equation (1) below;

2 HCOONa + H2SO4 ---------> 2 CO + 2 H2O + Na2SO4. ----------------------------------------------------------------------------(1).

From the balanced chemical reaction in equation (1) above we can see that; 2 moles of HCOONa reacts with one moles of tetraoxosulphate acid, H2SO4 to produce 2 moles of carbonmonoxide,CO; 2 moles of water, H2O and 1 mole of sodium tetraoxosulphate, Na2SO4.

The parameters given from the question are; total atmospheric pressure, P(t) = 752 torr, volume of CO= 242 mL = 0.242 Litres.

STEP ONE : find the carbon monoxide,CO pressure; P(CO).

Using the formula below;

P(t) = P(CO) + P(H2O). Hence;

P(CO) = P(t) - P(H2O). Note that P(H2O)= 19.8 torr.

==>P(CO)= 752 torr - 19.8 torr = 732.2 torr.

STEP TWO: calculate the number of moles of Carbonmonoxide,CO.

Using the formula below;

Number of moles= pressure(P) × volume(v) / gas constant(R) × temperature (T).

That is, n= PV/RT.

n= 732 torr × 0.242 Litres/ 62.4 × 295.15.

= 9.62 × 10^-3 mol of CO.

STEP THREE:

2 moles of HCOONa = 2 moles of CO.

=> 2 moles of HCOONa = 2 moles of CO/ 2 moles of CO = 1 mol( HCOONa/ CO).

Then, 9.62 × 10^-3 mol of CO × 1 mol( HCOONa/ CO).

==> 9.62 × 10^-3 mol HCOONa × molar masss of HCOONa(68 grams/mol)

= 0.654 grams.

Therefore, the percentage of sodium formate in the original mixture = 0.654 grams/ 0.964 gram × 100 = 67.8 %.

5 0

4 years ago

What kind of feature results from the convergence of two oceanic plates?

Liono4ka [1.6K]

Answer: When a convergent boundary occurs between two oceanic plates, one of those plates will subduct beneath the other. Normally the older plate will subduct because of its higher density. The subducting plate is heated as it is forced deeper into the mantle, and at a depth of about 100 miles (150 km) the plate begins to melt.

Explanation:

4 0

3 years ago

Many important biochemicals are organic acids, such as pyruvic acid ( p K a = 2.50 ) and lactic acid ( p K a = 3.86 ) . The conj

Ivenika [448]

Answer:

Pyruvic acid: conjugate base

Lactic acid: conjugate base

Explanation:

The ratio of conjugate base to conjugate acid can be found using the Henderson-Hasselbalch equation when the pH and pKa are known.

pH = pKa + log([A⁻]/[HA])

The equation can be rearranged to solve for the ratio:

pH - pKa = log([A⁻]/[HA])

[A⁻]/[HA] = 10^(pH-pKa)

Now we can calculate the ratio for the pyruvic acid:

[A⁻]/[HA] = 10^(pH-pKa) = 10^(7.4 - 2.50) = 79433

[A⁻] = 79433[HA]

There is a much higher concentration of the conjugate base.

Similarly for lactic acid:

[A⁻]/[HA] = 10^(pH-pKa) = 10^(7.4 - 3.86) = 3467

[A⁻] = 3467[HA]

For lactic acid the conjugate base also dominates at pH 7.4

6 0

4 years ago

A compound with molecular formula C6H15N exhibits a singlet at d 0.9 (1H), a triplet at d 1.10 (3H), a singlet at d1.15 (9H), an

LuckyWell [14K]

Answer:

N-ethyl-2-methylpropan-2-amine

Explanation:

In this case, we have to start with the IR info. The signal on 3400 cm^-1 indicates the presence of a hydrogen bonded to the heteroatom. In this case, we have nitrogen in the formula, so we will have the amine group.

On the other hand, we have to analyze the NMR info:

a) We have 2 singlets => This indicates the presence of 2 different hydrogens without neighbors.

b) We have a triplet => This indicates the presence of CH3 bonded to a CH2.

c) We have a quartet => This indicates the presence of CH2 bonded to a CH3.

From b) and c) we can conclude that we have the ethyl group bonded to a nitrogen.

Finally, we have to add 4 more carbons in such a way that we only have a single signal. In this case the ter-butyl group.

In that way, we will have 2 singlets (from the CH3 groups in the ter-butyl and the H on the N). Also, we will have the quartet on the CH2 in the ethyl group and the triplet on the CH3 in the ethyl group

6 0

3 years ago

What is the atomic number of an atom? Why is this number important?

aalyn [17]

The number of protons in an atom is called its atomic number. This number is very important because it is unique for atoms of a given element. All atoms of an element have the same number of protons, and every element has a different number of protons in its atoms

8 0

3 years ago