Which of these is NOT an example of physical change?

A solution is prepared by adding 0.0231moles of H3O+ ions to 3.33L of water. What is the pH of this solution

MrMuchimi

Answer:

2.15

Explanation:

For this question, we have to remember the pH formula:

$pH~=~-Log[H_3O^+]$

By definition, the pH value is calculated when we do the -Log of the concentration of the hydronium ions ( $H_3O^+$ ). So, the next step is the calculation of the concentration of the hydronium ions. For this, we have to use the molarity formula:

$M=\frac{mol}{L}$

We already know the number of moles (0.0231 moles) and the volume (3.33 L). So, we can plug the values into the molarity formula:

$M=\frac{0.0231~moles}{3.33~L}=0.00693~M$

With this value, now we can calculate the pH value:

$pH~=~-Log[0.00693~M]~=~2.15$

The pH would be 2.15

I hope it helps!

8 0

3 years ago

Why can’t you perform single displacement reactions with group IA metals?

pishuonlain [190]

Answer is: because alkaline metals (group IA metals) are the strongest reducing agents and most reactive metals.
Reducing agent is an element or compound that loses an electron to another chemical species in a redox chemical reaction and they have been oxidized.
Alkaline metals tend to lose only one electron in redox reaction.

5 0

3 years ago

Find the total number of moles of ions produced when 0.347 mol of sodium carbonate dissolves.

Ahat [919]

Answer:

molarity= 0.238 mol L-

Explanation:

The idea here is that you need to use the fact that all the moles of sodium phosphate that you dissolve to make this solution will dissociate to produce sodium cations to calculate the concentration of the sodium cations.

Na 3 PO 4 (aq) → Na + (aq) + PO3−4 (aq)

Use the molar mass of sodium phosphate to calculate the number of moles of salt used to make this solution.

3.25g⋅1 mole N 3PO4 163.9g = 0.01983 moles Na3 PO 4

Now, notice that every

1 mole of sodium phosphate that you dissolve in water dissociates to produce

3bmoles of sodium cations in aqueous solution.

4 0

2 years ago

A student decides to conduct an investigation to determine the boiling points of water and ethanol. The student will heat sample

lilavasa [31]

Deciding on the appropriate equipment

8 0

2 years ago

when 32.4 g of water vapor condenses, how much heat is given off? The heat of vaporization for water is 40.67 kj/mol

egoroff_w [7]

When a water vapor condenses, heat is being released from the process. This heat is called latent heat of vaporization since the phase change happens without any change in the temperature. This value is constant per mole of a substance as a function of pressure and temperature. For this problem, we are given the heat of vaporization at a certain T and P. We use this value to calculate the total heat released from the process. We calculate as follows:

Total heat released: 32.4 g ( 1 mol / 18.02 g ) (40.67 kJ / mol) = 73.12 kJ

Therefore, 73.12 kJ of heat is released from the condensation of 32.4 g of water vapor.

3 0

3 years ago