Compound X has a molar mass of 283.89 mol^-1 and the following composition:

What does the nucleus of a atom contain?

givi [52]

It contains neutrons, which have no charge. Protons which have a positive charge and electrons which have a negative charge. These are all called subatomic particles

3 0

2 years ago

consider an exceptionally weak acid, HA, with Ka= 1 x 10-20. you make 0.1M solution of the salt NA. what is the pH.

iogann1982 [59]

Answer:

$pH=10.5$

Explanation:

Hello,

In this case, the dissociation of the given weak acid is:

$HA\rightleftharpoons H^++A^-$

Therefore, the law of mass action for it turns out:

$Ka=\frac{[H^+][A^-]}{[HA]}$

That in terms of the change $x$ due to the reaction extent is:

$1x10^{-23}=\frac{x*x}{0.1-x}$

Thus, by solving with the quadratic equation or solver, we obtain:

$x=31.6x10^{-12}M$

Which clearly matches with the hydrogen concentration in the solution, therefore, the pH is:

$pH=-log(-31.6x10^{-12})\\pH=10.5$

Regards.

5 0

3 years ago

Which is easier to remove: a valence electron from, Li or Na? Explain why.

scZoUnD [109]

The atomic number of Li is 3

Electron configuration of Li : 1s² 2s¹

The atomic number of Na is 11

Electron configuration of Na : 1s²2s²2p⁶3s¹

Thus there is one electron in the valence shell of Li (2s¹) and that of Na (3s¹). However, the valence electron in Na is in a shell that is farther away from the nucleus compared to that of Li. As a result, the Na valence electron will be held less tightly by the nucleus i.e. it will experience a reduced nuclear attraction and can be removed easily than the Li 2s electron.

7 0

2 years ago

What is the oxidation half-reaction for this unbalanced redox equation? cr2o72– + fe2+ → cr3+ + fe3+ cr3+ → cr2o72– cr2o72– → cr

KatRina [158]

Answer:

6Fe^2+(aq) -------> 6Fe^3+(aq) + 6e

Explanation:

The balanced oxidation half equation is;

6Fe^2+(aq) -------> 6Fe^3+(aq) + 6e

A redox reaction is actually an acronym for oxidation-reducation reaction. Since the both reactions are complementary, there can't be oxidation without reduction and there can't be reduction without oxidation.

The main characteristic of redox reactions is that electrons are transferred in the process. The number of electrons transferred is usually deduced from the balanced reaction equation. For this reaction, the balanced overall reaction equation is;

Cr2O7^2–(aq) + 6Fe^2+(aq) +14H^+(aq)→ 2Cr^3+(aq) + 6Fe^3+ (aq) + 7H2O(l)

It is clear from the equation above that six electrons were transferred. Thus six Fe^2+ ions lost one electron each in the oxidation half equation as shown in the balanced oxidation half equation above.

4 0

3 years ago

Titanium is a transition metal used in many alloys because it is extremely strong and lightweight. Titanium tetrachloride (TiCl4

vova2212 [387]

Answer:

a) 226.6 grams of Cl₂

b) 19.2 grams of C

c) 303.2 grams of TiCl₄ and 70.4 grams of CO₂

Explanation:

The balanced chemical reaction is the following:

TiO₂(s) + C(s) + 2 Cl₂(g) → TiCl₄(s) + CO₂(g)

(a) What mass of Cl₂ gas is needed to react with 1.60 mol TiO₂?

From the chemical equation, 1 mol of TiO₂ reacts with 2 moles of Cl₂. So, the stoichiometric ratio is 2 mol Cl₂/1 mol TiO₂. We multiply this ratio by the moles of TiO₂ we have to calculate the moles of Cl₂ we need:

1.60 mol TiO₂ x 2 mol Cl₂/1 mol TiO₂ = 3.2 mol Cl₂

Now, we convert from moles to mass by using the molecular weight (MW) of Cl₂:

MW(Cl₂) = 35.4 g/mol x 2 = 70.8 g/mol

mass of Cl₂= 3.2 mol x 70.8 g/mol = 226.6 g

Therefore, 226.6 grams of Cl₂ are needed to react with 1.6 mol of TiO₂.

(b) What mass of C is needed to react with 1.60 mol of TiO₂?

From the chemical equation, 1 mol of TiO₂ reacts with 1 moles of C(s). So, the stoichiometric ratio is 1 mol C/1 mol TiO₂. We multiply this ratio by the moles of TiO₂ we have to calculate the moles of C(s) we need:

1.60 mol TiO₂ x 1 mol C(s)/1 mol TiO₂ = 1.60 mol C(s)

So, we convert the moles of C(s) to grams as follows:

MW(C) = 12 g/mol

1.60 mol x 12 g/mol = 19.2 g C(s)

Therefore, a mass of 19.2 grams of C is needed to react with 1.60 mol of TiO₂.

(c) What is the mass of all the products formed by reaction with 1.60 mol of TiO₂?

From the chemical equation, we can notice that 1 mol of TiO₂ produces 1 mol of TiCl₄ and 1 mol of CO₂. So, from 1.60 moles of TiO₂, 1 mol of each product will be produced:

1 mol TiO₂/1 mol TiCl₄ ⇒ 1.60 mol TiO₂/1.60 mol TiCl₄

1 mol TiO₂/1 mol CO₂ ⇒ 1.60 mol TiO₂/1.60 mol CO₂

Finally, we convert the moles to grams by using the molecular weight of each compound:

MW(TiCl₄) = 47.9 g/mol Ti + (35.4 g/mol x 4 Cl) = 189.5 g/mol

1.60 mol x 189.5 g/mol = 303.2 g

MW(CO₂) = 12 g/mol C + (16 g/mol x 2 O) = 44 g/mol

1.60 mol x 44 g/mol = 70.4 g

Therefore, from the reaction of 1.60 mol of TiO₂ are formed 303.2 grams of TiCl₄ and 70.4 grams of CO₂.

3 0

3 years ago