All categories

4 years ago

Which of these has a higher hydrogen ion concentration? *

Chemistry

1 answer:

Genrish500 [490]4 years ago

8 0

Answer:

pOH = 8.9

Explanation:

pOH+pH = 14

pH= 14- pOH

pOH = 8.9, pH=14-8.9 = 5.1

pOH = 5.5, pH=14-5.5 = 8.5

Than less pH , than more H+ ion concentration.

pH=5.1 <pH=8.5

pH=5.1 is more acidic solution

pH=5.1 or pOH=8.9 has a higher H+ concentration.

You might be interested in

The average molecular weight for element X is 59.97 g/mol. There are two known isotopes of element X, one weighing 59 g/mol, and

Temka [501]

Answer:

The correct answer is:48.5% X-59, 51.5% X-61

Explanation:

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

$\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i$ .....(1)

Let the fractional abundance of X-59 isotope be 'x'. So, fractional abundance of X-61 isotope will be '1 - x'

For X-59 isotope:

Mass of X-59 isotope =59 g/mol

Fractional abundance of X-59 isotope = x

For X-61 isotope:

Mass of X-61 isotope = 61 g/mol

Fractional abundance of X-61 isotope = 1 - x

Average atomic mass of chlorine = 35.4527 amu

Putting values in equation 1, we get:

$59.97 g/mol=[(59 g/mol\times x)+(61 g/mol\times (1-x))]\\\\x=0.515$

Percentage abundance of X-59 isotope = $0.515\times 100=51.5\%$

Percentage abundance of X-61 isotope = $(1-0.515)=0.485\times 100=48.5\%$

Hence, the percentage abundance of both the isotopes X-59and X-61 are 51.5% and 48.5% respectively.

4 0

3 years ago

At 298 K, what is the Gibbs free energy change (ΔG) for the following reaction?

9966 [12]

Answer:

(a). The Gibbs free energy change is 2.895 kJ and its positive.

(b). The Gibbs free energy change is 34.59 J/mole

(c). The pressure is 14924 atm.

(d). The Gibbs free energy of diamond relative to graphite is 4912 J.

Explanation:

Given that,

Temperature = 298 K

Suppose, density of graphite is 2.25 g/cm³ and density of diamond is 3.51 g/cm³.

$\Delta H\ for\ diamond = 1.897 kJ/mol$

$\Delta H\ for\ graphite = 0 kJ/mol$

$\Delta S\ for\ diamond = 2.38 J/(K mol)$

$\Delta S\ for\ graphite = 5.73 J/(K mol)$

(a) We need to calculate the value of $\Delta G$ for diamond

Using formula of Gibbs free energy change

$\Delta G=\Delta H-T\Delta S$

Put the value into the formula

$\Delta G= (1897-0)-298\times(2.38-5.73)$

$\Delta G=2895.3$

$\Delta G=2.895\ kJ$

The Gibbs free energy change is positive.

(b). When it is compressed isothermally from 1 atm to 1000 atm

We need to calculate the change of Gibbs free energy of diamond

Using formula of gibbs free energy

$\Delta S=V\times\Delta P$

$\Delta S=\dfrac{m}{\rho}\times\Delta P$

Put the value into the formula

$\Delta S=\dfrac{12\times10^{-6}}{3.51}\times999\times10130$

$\Delta S=34.59\ J/mole$

(c). Assuming that graphite and diamond are incompressible

We need to calculate the pressure

Using formula of Gibbs free energy

$\beta= \Delta G_{g}+\Delta G+\Delta G_{d}$

$\beta=V(-\Delta P_{g})+\Delta G+V\Delta P_{d}$

$\beta=\Delta P(V_{d}-V_{g})+\Delta G$

Put the value into the formula

$0=\Delta P(\dfrac{12\times10^{-6}}{3.51}-\dfrac{12\times10^{-6}}{2.25})\times10130+2895.3$

$0=-0.0194\Delta P+2895.3$

$\Delta P=\dfrac{2895.3}{0.0194}$

$\Delta P=14924\ atm$

(d). Here, $C_{p}=0$

So, The value of $\Delta H$ and $\Delta S$ at 900 k will be equal at 298 K

We need to calculate the Gibbs free energy of diamond relative to graphite

Using formula of Gibbs free energy

$\Delta G=\Delta H-T\Delta S$

Put the value into the formula

$\Delta G=(1897-0)-900\times(2.38-5.73)$

$\Delta G=4912\ J$

Hence, (a). The Gibbs free energy change is 2.895 kJ and its positive.

(b). The Gibbs free energy change is 34.59 J/mole

(c). The pressure is 14924 atm.

(d). The Gibbs free energy of diamond relative to graphite is 4912 J.

7 0

3 years ago

A 1.0857 gram pure sample of a compound containing only carbon, hydrogen, and oxygen was burned in excess oxygen gas. 2.190 g of

Goryan [66]

Answer:

C₂ H₄ O

Explanation:

1) Mass of carbon (C) in 2.190 g of carbon dioxide (CO₂)

atomic mass of C: 12.0107 g/mol

molar mass of CO₂: 44.01 g/mol

Set a proportion: 12.0107 g of C / 44.01 g of CO₂ = x / 2.190 g of CO₂

Solve for x:

x = (12.0107 g of C / 44.01 g of CO₂ ) × 2.190 g of CO₂ = 0.59767 g of C

2) Mass of hydrogen (H) in 0.930 g of water (H₂O)

atomic mass of H: 1.00784 g/mol

molar mass of H₂O: 18.01528 g/mol

proportion: 2 × 1.00784 g of H / 18.01528 g of H₂O = x / 0.930 g of H₂O

Solve for x:

x = ( 2 × 1.00784 g of H / 18.01528 g of H₂O) × 0.930 g of H₂O = 0.10406 g of H

3) Mass of oxygen (O) in 1.0857 g of pure sample

Mass of O = mass of pure sample - mass of C - mass of H

Mass of O = 1.0857 g - 0.59767 g - 0.10406 = 0.38397 g O

Round to four decimals: Mass of O = 0.3840 g

4) Mole calculations

Divide the mass in grams of each element by its atomic mass:

C: 0.59767 g / 12.0107 g/mol = 0.04976 mol

H: 0.10406 g / 1.00784 g/mol = 0.10325 mol

O: 0.3840 g / 15.999 g/mol = 0.02400 mol

5) Divide every amount by the smallest value (to find the mole ratios)

C: 0.04976 mol / 0.02400 mol = 2.07 ≈ 2

H: 0.10325 mol / 0.02400 mol = 4.3 ≈ 4

O: 0.02400 mol / 0.02400 mol = 1

Thus the mole ratio is 2 : 4 : 1, and the empirical formula is:

C₂ H₄ O ← answer

3 0

3 years ago

What is the area of an atom with the least amount of mass?

Vlad1618 [11]

The electron cloud has the least amount of space.

6 0

4 years ago

How many molecules are in a mole 0.500 mile of N205

kirill [66]

D answer is D and that is your answer

5 0

3 years ago