Which term defines the following: moles of solute mass of solvent in kg?

An ice cube is placed in a plastic cup on the lab table. Students record the mass of the ice cube and the plastic cup as 5 grams

bagirrra123 [75]

The answer is still 5 grams because mass can not be changed or destroyed.

7 0

4 years ago

A) Calculate the pH of a 1.8 * 10 -4 M HCl solution

Sergio [31]

Answer:-

A) 3.745

B) 2 x 10^-13 M [H+]

pOH = 1.3

Explanation:-

A) From the question we see

The strength of HCl solution = 1.8 x 10^-4 M.

The M stands for molarity which is moles / Litre.

HCl is a monobasic acid. So the number of moles of Hydrogen ion H+ HCl can give is the same as the value of it’s strength in moles per litre.

The hydrogen ion concentration [H+] is therefore 1.8 x 10^-4.

The formula for pH is

pH = - log [ H+ ]

= - log [1.8 x 10^-4]

= 3.745

B) From the question we see

The strength of KOH = 0.05 M

The M stands for molarity which is moles / Litre.

KOH is a monoacidic base. So the number of moles of Hydroxyl ion OH- KOH can give is the same as the value of it’s strength in moles per litre.

The Hydroxyl ion concentration [OH-] is therefore 0.05

The relation between [OH-] and [H+] is

[H+] x [ OH-] = 10^-14

[H+] = 10^-14 / [OH-]

= 10^-14/ 0.05

= 2 x 10^-13 M

Using the relation between pH and [OH-]

pOH = - log [OH-]

= -log [0.05]

= 1.3

7 0

3 years ago

In methane combustion, the following reaction pair is important: At 1500 K, the equilibrium constant Kp has a value of 0.003691

andre [41]

Explanation:

Let us assume that the value of $K_{r}$ = $2.82 \times 10^{5} \times e^({\frac{-9835}{T}}) m^{6}/mol^{2}s$

Also at 1500 K, $K_{r}$ = $2.82 \times 10^{5} \times e^({\frac{-9835}{1500}}) m^{6}/mol^{2}s$

$K_{r} = 400.613 m^{6}/mol^{2}s$

Relation between $K_{p}$ and $K_{c}$ is as follows.

$K_{p} = K_{c}RT$

Putting the given values into the above formula as follows.

$K_{p} = K_{c}RT$

$0.003691 = K_{c} \times 8.314 \times 1500$

$K_{c} = 2.9 \times 10^{-7}$

Also, $K_{c} = \frac{K_{f}}{K_{r}}$

or, $K_{f} = K_{c} \times K_{r}$

= $2.9 \times 10^{-7} \times 400.613$

= $1.1617 \times 10^{-4} m^{6}/mol^{2}s$

Thus, we can conclude that the value of $K_{f}$ is $1.1617 \times 10^{-4} m^{6}/mol^{2}s$ .

6 0

3 years ago

Which element donates hydrogen ions when dissolved in water?acidsbasessalts?

ohaa [14]

According to bronsted theory

Acid is a substance that donate hydrogen ion ( proton ) when disolved in water ..

5 0

4 years ago

What is the electronic configuration for Sodium chloride ?

Tomtit [17]

Answer:

The electronic configuration of Na+ in NaCl is 2, 8, and of Cl- is 2, 8, 8.

4 0

3 years ago