What type of change is this picture showing?

A reaction that had two compounds as reactants and two compounds as products is most likely a

sergejj [24]

double-replacement reaction

5 0

2 years ago

For the reaction: CH3NH2(aq) + H2O(aq) ⇌ CH3NH3 +(aq) + OH- Determine the change in the pH (ΔpH) for the addition of 6.7 M CH3NH

Korolek [52]

Answer:

The change in the pH (ΔpH) is 2,17

Explanation:

The reaction:

CH₃NH₂(aq) + H₂O(aq) ⇌ CH₃NH₃⁺(aq) + OH⁻

$kb = \frac{[OH^{-}][CH_{3}NH_{3}^+]}{[CH_{3}NH_{2}]}$ (1)

In equilibrium, a solution of CH₃NH₂ 4,7M produces:

[CH₃NH₂] = 4,7 - x

[CH₃NH₃⁺] = x

[OH⁻] = x

Replacing in (1):

$4,38x10^{-4} = \frac{x^2}{4,7-x}$

x² + 4,38x10⁻⁴x - 2,0586x10⁻³ = 0

The solutions are:

x = -0,0456 No physical sense. There are not negative concentrations.

x = 0,04515 Real answer.

The concentration of [OH⁻] is 0,04515 M.

As pOH = -log [OH⁻] And pH+pOH = 14. The pH of this solution is:

pH = 12,65

The addition of 6,7M produce this changes in concentrations:

[CH₃NH₂] = 4,656 + x

[CH₃NH₃⁺] = 6,74515 - x

[OH⁻] = 0,04515 - x

Replacing in (1) you will obtain:

x² - 6,7907x + 0,3025 = 0

Solving for x:

x = 6,74586 No physical sense

x = 0,04484 Real answer.

Thus, [OH⁻] = 0,04515 - 0,044842 = 3,08x10⁻⁴M

pOH = 3,51.

pH = 10,49

Thus ΔpH is 12,65 - 10,49 = 2,16 ≈ 2,17

I hope it helps!

4 0

3 years ago

Which gas law states that the pressure of a gas decreases when volume is increased and the temperature is unchanged

Nesterboy [21]

Answer: Boyle's law

Explanation: It states that pressure of a gas is inversely proportional to the volume of a gas at constant temperature.

$P$ ∝ $\frac{1}{V}$ at constant temperature

or If the pressure of gas is decreased, the volume increases if the temperature is unchanged and If the pressure of gas is increased, the volume decreases if the temperature is unchanged.

$P_1V_1=P_2V_2$

3 0

3 years ago

Read 2 more answers

What is he empirical formula for the compound that is of 1.85 moles of nitrogen and 4.63 miles of oxygen

BartSMP [9]

The empirical formula is N₂O₅.

The empirical formula is the simplest whole-number ratio of atoms in a compound.

The ratio of atoms is the same as the ratio of moles, so our job is to calculate the molar ratio of N:O.

I like to summarize the calculations in a table.

Element Moles Ratio¹ ×2² Integers³

N 1.85 1 2 2

O 4.63 2.503 5.005 5

¹To get the molar ratio, you divide each number of moles by the smallest number (1.85).

²Multiply these values by a number (2) that makes the numbers in the ratio close to integers.

³Round off the number in the ratio to integers (2 and 5).

The empirical formula is N₂O₅.

4 0

3 years ago

2 NO + O22 NO2 is second order in NO and first order in O2. Complete the rate law for this reaction in the box below. Use the fo

riadik2000 [5.3K]

Answer : The value of rate of reaction is $1.35\times 10^{-8}Ms^{-1}$

Explanation :

Rate law : It is defined as the expression which expresses the rate of the reaction in terms of molar concentration of the reactants with each term raised to the power their stoichiometric coefficient of that reactant in the balanced chemical equation.

The given chemical equation is:

$2NO+O_2\rightarrow 2NO_2$