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2 years ago

Determine the total number of moles of ions in 40.0 ml of a 0.345 m solution of the strong electrolyte mgcl2

1 answer:

6 0

A strong electrolyte like MgCl2 dissociates completely as per the following reaction:

$MgCl_2 ----\ \textgreater \ Mg^{2+} + 2Cl^-$

As you can see, from 1 molecule of MgCl2 produces 3 ions on dissociation.
So, 1 mole of MgCl2 produces 3 moles of ions.

Now, Moles of MgCl2 = Volume x Molarity

= 0.04 x 0.345 [Change volume to Litres]
= 0.0138 moles

Now, total moles of ions = 0.0138 x 3 = 0.0414

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A 5 mole sample of liquid acetone is converted to a gas at 75.0°C. If 628 J are required to raise the temperature of the liquid

Shkiper50 [21]

The total energy can be found by adding the different energies:
628 + 15,600 + 712
= 16.94 kJ

4 0

2 years ago

If an equal number of moles of reactants are used, do the following equilibrium mixtures contain primarily reactants or products

puteri [66]

Answer:

For a: The equilibrium mixture contains primarily reactants.

For b: The equilibrium mixture contains primarily products.

Explanation:

There are 3 conditions:

When $K_{eq}>1$ ; the reaction is product favored.
When $K_{eq}$ ; the reaction is reactant favored.
When $K_{e}=1$ ; the reaction is in equilibrium.

For the given chemical reactions:

For a:

The chemical equation follows:

$HCN(aq.)+H_2O(l)\rightleftharpoons CN^-(aq.)+H_3O^+(aq.);K_{eq}=6.2\times 10^{-10}$

The expression of $K_{eq}$ for above reaction follows:

$K_{eq}=\frac{[CN^-][H_3O^+]}{[HCN][H_2O]}=6.2\times 10^{-10}$

As, $K_{eq}$ , the reaction will be favored on the reactant side.

Hence, the equilibrium mixture contains primarily reactants.

For b:

The chemical equation follows:

$H_2(g)+Cl_2(g)\rightleftharpoons 2HCl(g);K_{eq}=2.51\times 10^{4}$

The expression of $K_{eq}$ for above reaction follows:

$K_{eq}=\frac{[HCl]^2}{[H_2][Cl_2]}=2.51\times 10^{4}$

As, $K_{eq}>1$ , the reaction will be favored on the product side.

Hence, the equilibrium mixture contains primarily products.

4 0

2 years ago

When CO2(g) reacts with H2(g) to form C2H2(g) and H2O(g), 23.3 kJ of energy are absorbed for each mole of CO2(g) that reacts. Wr

kupik [55]

Answer:

$2CO_{2}(g)+5H_{2}(g)\rightarrow C_{2}H_{2}(g)+4H_{2}O(g)-46.6kJ$

Explanation:

As energy is absorbed therefore it is an endothermic reaction. Hence energy value should be written in the product side with a negative sign.

Reaction: $CO_{2}(g)+H_{2}(g)\rightarrow C_{2}H_{2}(g)+H_{2}O(g)$

C balance: $2CO_{2}(g)+H_{2}(g)\rightarrow C_{2}H_{2}(g)+H_{2}O(g)$

H and O balance: $2CO_{2}(g)+5H_{2}(g)\rightarrow C_{2}H_{2}(g)+4H_{2}O(g)$

Here 2 moles of $CO_{2}$ react. So, energy absorbed during the reaction is $(2\times 23.3)$ kJ or 46.6 kJ

Energy balance: $2CO_{2}(g)+5H_{2}(g)\rightarrow C_{2}H_{2}(g)+4H_{2}O(g)-46.6kJ$

Balanced thermochemical equation:

$2CO_{2}(g)+5H_{2}(g)\rightarrow C_{2}H_{2}(g)+4H_{2}O(g)-46.6kJ$

3 0

2 years ago

Assuming that the experiments performed in the absence of inhibitors were conducted by adding 5 μl of a 2 mg/ml enzyme stock sol

prohojiy [21]

Hey there!:

From the given data ;

Reaction volume = 1 mL , enzyme content = 10 ug ( 5 ug in 2 mg/mL )

Enzyme mol Wt = 45,000 , therefore [E]t is 10 ug/mL , this need to be express as "M" So:

[E]t in molar = g/L * mol/g

[E]t = 0.01 g/L * 1 / 45,000

[E]t = 2.22*10⁻⁷

Vmax = 0.758 umole/min/ per mL

= 758 mmole/L/min

=758000 mole/L/min => 758000 M

Therefore :

Kcat = Vmax/ [E]t

Kcat = 758000 / 2.2*10⁻⁷ M

Kcat = 3.41441 *10¹² / min

Kcat = 3.41441*10¹² / 60 per sec

Kcat = 5.7*10¹⁰ s⁻¹

Hence kcat of xyzase is 5.7*10¹⁰ s⁻¹

Hope that helps!

4 0

2 years ago

Metals with ________ electron configurations characteristically form diamagnetic, square planar complexes.

erastovalidia [21]

Answer:

Explanation:

Diamagnetism , paramagnetism and ferromagnetism are terms which are used to describe the magnetic activity of transition metals. These terms helps to know the response the metal will have when placed in a magnetic field. These activities can be discerned from the d-block electronic configuration. If the number of electrons are even, this means they all form a pair and the metal is diamagnetic. If otherwise, there is an unpaired electron which causes the paramagnetic activity of the metal in magnetic field.

To the question, options A-D are diamagnetic but configurations with d8 are the ones that form square planar complexes

8 0

2 years ago