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3 years ago

3. Which of the following is the correct mathematical expression to use to

Chemistry

1 answer:

xxTIMURxx [149]3 years ago

8 0

Answer:

The pH of a 0.10 Maqueous Ba(OH)2 solution at 25°C is 13.30

Explanation:

The balanced equation is Ba(OH)2(s)→Ba2++2OH−

This indicates that the concentration is 0.2 M

We will find H+ ion concentration

As we know that

[H+][OH−]=1.0×10−14M

Given -

[OH−]=2.0×10−1M

Putting value of [OH-] in above equation we get -

[H+]=5.0×10−14M

pH=−log10[H+]

pH=−log10[5.0×10−14] = 13.30.

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Hillsdale and Cordera are the same distance from the equator, and both are near the ocean. Is Cordera warmer, colder, or the sam

kozerog [31]

Answer:

Cordera is colder than Hillsdale.

Explanation:

They may be at a similar latitude. But you also have to consider the currents nearby the location.

The prevailing wind closer to the equator which carries warm current hits Hillsdale which is why it follows the coastline of the continent. However, for Cordera prevailing winds carrying cold currents hits the continent and follows or hits the coastline of Cordera.

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3 years ago

What describes a phase change

Finger [1]

A phase change is when matter changes to from one state ( solid, liquid, gas, plasma) to another.

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3 years ago

An atom has 9 electrons and 9 protons at the start . If it loses 2 electrons, the net charge on the atom will be ? If the atom i

antoniya [11.8K]

Loses 2= +2 charge
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3 years ago

Read 2 more answers

Calculate the initial rate for the formation of C at 25 ∘C, if [A]=0.50M and [B]=0.075M.Express your answer to two significant f

N76 [4]

The question is incomplete, here is the complete question:

Calculate the initial rate for the formation of C at 25°C, if [A]=0.50 M and [B]=0.075 M. Express your answer to two significant figures and include the appropriate units.Consider the reaction

A + 2B ⇔ C

whose rate at 25°C was measured using three different sets of initial concentrations as listed in the following table:

The table is attached below as an image.

<u>Answer:</u> The initial rate for the formation of C at 25°C is $2.25\times 10^{-2}Ms^{-1}$

<u>Explanation:</u>

Rate law 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.

For the given chemical equation:

$A+2B\rightleftharpoons C$

Rate law expression for the reaction:

$\text{Rate}=k[A]^a[B]^b$

where,

a = order with respect to A

b = order with respect to B

Expression for rate law for first trial:

$5.4\times 10^{-3}=k(0.30)^a(0.050)^b$ ....(1)

Expression for rate law for second trial:

$1.1\times 10^{-2}=k(0.30)^a(0.100)^b$ ....(2)

Expression for rate law for third trial:

$2.2\times 10^{-2}=k(0.50)^a(0.050)^b$ ....(3)

Dividing 2 by 1, we get:

$\frac{1.1\times 10^{-2}}{5.4\times 10^{-3}}=\frac{(0.30)^a(1.00)^b}{(0.30)^a(0.050)^b}\\\\2=2^b\\b=1$

Dividing 3 by 1, we get:

$\frac{2.2\times 10^{-2}}{5.4\times 10^{-3}}=\frac{(0.50)^a(0.050)^b}{(0.30)^a(0.050)^b}\\\\4.07=2^a\\a=2$

Thus, the rate law becomes:

$\text{Rate}=k[A]^2[B]^1$ ......(4)

Now, calculating the value of 'k' by using any expression.

Putting values in equation 1, we get:

$5.4\times 10^{-3}=k[0.30]^2[0.050]^1\\\\k=1.2M^{-2}s^{-1}$

Calculating the initial rate of formation of C by using equation 4, we get:

$k=1.2M^{-2}s^{-1}$

[A] = 0.50 M

[B] = 0.075 M

Putting values in equation 4, we get:

$\text{Rate}=1.2\times (0.50)^2\times (0.075)^1\\\\\text{Rate}=2.25\times 10^{-2}Ms^{-1}$

Hence, the initial rate for the formation of C at 25°C is $2.25\times 10^{-2}Ms^{-1}$

8 0

3 years ago

A compound with molecular formula C6H15N exhibits a singlet at d 0.9 ppm (1H), a triplet at 1.10 ppm (3H), a singlet at 1.15 ppm

Triss [41]

Answer:

CH3 - CH2 - NH - C(CH3)3

Explanation:

The 1HNMR is the acronym for Proton nuclear magnetic resonance and it is used in chemistry or Chemical laboratory for the analysis and identification of compounds.

In order to be able to answer the question accurately you have to have the tables containing all the values for chemical shift. The Chemical shift is measured in ppm and it occur due to Resonance frequency variation.

From the table, a singlet at 1.15 ppm (9H) is - C(CH3)3.

A singlet at d 0.9 ppm (1H) shows the presence of a secondary amine group, that is -R2NH group.

A triplet at 1.10 ppm (3H) shows that we have;

CH3- CH2-

A quartet at 2.6 ppm (2H) shows that we have;

-CH2 - CH3.

Therefore, joining all together we have;

CH3 - CH2 - NH - C(CH3)3.

Kindly check attached file for the picture of the structure.

5 0

3 years ago