What is the molarity of a solution in which 0.257 moles of HNO2 is dissolved in 490ml of water?

1. A solution is always a mixture (true or false)

lakkis [162]

Answer:

yes solution is always a mixture but not all mixtures are solution

Explanation:

A solution.is a homogeneous mixture of substance that have uniform composition throughout

And a mixture hVe twoo or more substances that are not chemically.combine

4 0

3 years ago

Consider the following reaction at equilibrium: 2NH3 (g) N2 (g) + 3H2 (g) Le Châtelier's principle predicts that the moles of H2

Lilit [14]

Answer:

A decrease in the total volume of the reaction vessel (T constant)

Explanation:

Le Châtelier's principle predicts that the moles of H2 in the reaction container will increase with a decrease in the total volume of the reaction vessel.
According to the Le Chatelier's principle, when a chnage is a applied to a system at equilibrium, then the equilibrium will shift in a way that counteracts the effect causing it.
In this case, a decrease in volume means there is an increase in pressure, therefore the equilibrium will shift towards the side with the fewer number of moles of gas.

3 0

3 years ago

The molar mass of an unknown gas was measured by an effusion experiment. It was found that it took 60 s for the gas to effuse, w

Marizza181 [45]

Answer:

The molar mass of the gas is 44 g/mol

Explanation:

It is possible to solve this problem using Graham's law that says: Rates of effusion are inversely dependent on the square of the mass of each gas. That is:

$\frac{r_1}{r_2} =\frac{\sqrt{M_2} }{\sqrt{M_1} }$

If rate of effusion of nitrogen is Xdistance / 48s and for the unknown gas is X distance / 60s and mass of nitrogen gas is 28g/mol (N₂):

$\frac{X/48s}{X/60s} =\frac{\sqrt{M_2} }{\sqrt{28g/mol} }$

6,61 = √M₂

44g/mol = M₂

The molar mass of the gas is 44 g/mol

I hope it helps!

4 0

3 years ago

Phosgene, a poisonous gas, when heated will decompose into carbon monoxide and chlorine in a reversible reaction: COCl2 (g) <

Advocard [28]

Answer:

8.08 × 10⁻⁴

Explanation:

Let's consider the following reaction.

COCl₂(g) ⇄ CO (g) + Cl₂(g)

The initial concentration of phosgene is:

M = 2.00 mol / 1.00 L = 2.00 M

We can find the final concentrations using an ICE chart.

COCl₂(g) ⇄ CO (g) + Cl₂(g)

I 2.00 0 0

C -x +x +x

E 2.00 -x x x

The equilibrium concentration of Cl₂, x, is 0.0398 mol / 1.00 L = 0.0398 M.

The concentrations at equilibrium are:

[COCl₂] = 2.00 -x = 1.96 M

[CO] = [Cl₂] = 0.0398 M

The equilibrium constant (Keq) is:

Keq = [CO].[Cl₂]/[COCl₂]

Keq = (0.0398)²/1.96

Keq = 8.08 × 10⁻⁴

4 0

3 years ago

Draw the molecule by placing atoms on the grid and connecting them with bonds. Include all lone pairs of electrons. Show the for

Alexus [3.1K]

Answer:

See explanation below

Explanation:

In this case, let's see both molecules per separate:

In the case of SeO₂ the central atom would be the Se. The Se has oxidation states of 2+, and 4+. In this molecule it's working with the 4+, while oxygen is working with the 2- state. Now, how do we know that Se is working with that state?, simply, let's do an equation for it. We know that this molecule has a formal charge of 0, so:

Se = x

O = -2

x + (-2)*2 = 0

x - 4 = 0

x = +4.

Therefore, Selenium is working with +4 state, the only way to bond this molecule is with a covalent bond, and in the case of the oxygen will be with double bond. See picture below.

In the case of CO₂ happens something similar. Carbon is working with +4 state, so in order to stabilize the charges, it has to be bonded with double bonds with both oxygens. The picture below shows.

5 0

3 years ago