What is the percent by mass of oxygen in mg(oh)2

Given the following equilibrium constants: Kb B(aq) + H2O(l) ⇌ HB+(aq) + OH−(aq) 1/Kw H+(aq) + OH−(aq) ⇌ H2O(l) What is the equi

bija089 [108]

Answer: The value of $K_c$ for the net reaction is $\frac{K_b}{K_w}$

Explanation:

The given chemical equations follows:

Equation 1: $B(aq.)+H_2O(l)\rightleftharpoons HB^+(aq.)+OH^-(aq.);K_b$

Equation 2: $H^+(aq.)+OH^-(aq.)\rightleftharpoons H_2O(l);\frac{1}{K_w}$

The net equation follows:

$B(aq.)+H^+(aq.)\rightleftharpoons HB^+(aq.);K_c$

As, the net reaction is the result of the addition of first equation and the second equation. So, the equilibrium constant for the net reaction will be the multiplication of first equilibrium constant and the second equilibrium constant.

The value of equilibrium constant for net reaction is:

$K_c=K_1\times K_2$

We are given:

$K_1=K_b$

$K_2=\frac{1}{K_w}$

Putting values in above equation, we get:

$K_c=K_b\times \frac{1}{K_w}=\frac{K_b}{K_w}$

Hence, the value of $K_c$ for the net reaction is $\frac{K_b}{K_w}$

7 0

3 years ago

What would you use to mesuasee the height of the tree

Zielflug [23.3K]

Answer:

if you mean "measure" you can use many things. from inches to meters. sometimes if they are big they are measured in "stories". but the smaller the unit is. the harder it is and longer it takes to measure it

7 0

3 years ago

rank the following list of aqueous solutions and solvents according to decreasing vapor pressure the substance with the higher v

Tpy6a [65]

Answer: 0.050M urea, 0.10M glucose, 0.2M sucrose, pure water

Explanation:

Vapor pressure refers to the ease with which a liquid substance is transformed into vapour. High vapour density implies that the liquid is easily transformed into gas. Pure water is expected to have the lowest vapour density since it is held by strong intermolecular forces in the liquid state. Urea is an organic liquid held by weak Van der Waals forces hence its extremely high vapor pressure.

8 0

3 years ago

A quantity of 1.922 g of methanol (CH3OH) was burned in a constant-volume bomb calorimeter. Consequently, the temperature rose b

dezoksy [38]

Answer:

872.28 kJ/mol

Explanation:

The heat released is:

ΔH = C*ΔT

where ΔH is the heat of combustion, C is the heat capacity of the bomb plus water, and ΔT is the rise of temperature. Replacing with data:

ΔH = 9.47*5.72 = 54.1684kJ

A quantity of 1.922 g of methanol in moles are:

moles = mass / molar mass

moles = 1.992/32.04 = 0.0621 mol

Then the molar heat of combustion of methanol is:

ΔH/moles = 54.1684/0.0621 = 872.28 kJ/mol

5 0

3 years ago

Calculate the amount of heat needed to boil of benzene (), beginning from a temperature of . Be sure your answer has a unit symb

Pavlova-9 [17]

Answer:

Check explanation

Explanation:

From the question, the parameters given are 64.7g of benzene,C6H6; a starting temperature of 41.9°C and bringing it to 33.2°C.

Molar mass of benzene,C6H6= 78.11236 g/mol.

Things to know: heat capacity of benzene, C6H6= 1.63 J/g.K, the heat of fusion = 9.87 kj/mol.

STEP ONE(1): ENERGY USED IN MELTING BENZENE SOLID.

Using the formula below;

Energy used in melting the solid(in JOULES) = (mass of benzene/molar mass of benzene) × heat of Fusion.

=(64.7 g of C6H6/ 78.11236(g per mol) of C6H6) × 9.87 kJ per mol.

= 8.175 J.

= 0.008175 kJ.

STEP TWO (2): ENERGY OF HEATING THE LIQUID.

It can be calculated from the formula below;

Energy= heat capacity (J/g.K) × mass of benzene× (∆T).

= 1.63 J/g.K × 64.7 × (41.9-33.2).

= 917.5J.

= 0.9175 kJ.

Energy required to boil benzene= Energy required to melt the bezene + energy required for boiling.

= 0.008175+ 0.9175.

= 0.93kJ

Approximately, 1 kJ

8 0

2 years ago