Can u please help me with these 2 answers!

A substance with a ph of 9 has

Arisa [49]

Answer:

c) more OH⁻ ions than H₃O⁺ ions

Explanation:

A substance with a PH of 9 implies that it has more OH⁻ ions than H₃O⁺ ions.

Such substances are said to be an alkaline or a base.

A base is a substance the produces excess hydroxyl ion in aqueous solutions.

An acid will produce excess hydroxonium ions in a solution.

So, the pH scale is used to indicate whether a substance is an acid or base or non of them.

Acids have pH of less than 7

Bases have pH of > 7

4 0

3 years ago

while ionic compounds in the solid state do not conduct electricity, when they are melted, electric current

evablogger [386]

Answer:

Explanation:

Ionic (or electrovalent) compounds conduct electricity when there they are in the aqueous state/solution because the charges of ions of these compounds are what carry the electric charges in the aqueous solution as a result of free movement within the aqueous solution which they do not "have" when in there solid state (where they have a highly restricted movement/compacted structure).

3 0

3 years ago

What is the composition, in atom percent, of an alloy that consists of a) 5.5 wt% Pb and b) 94.5 wt% of Sn? Assume that the atom

Anastaziya [24]

Answer : The percent composition of Pb and Sn in atom is, 3.21 % and 96.8 % respectively.

Explanation :

First we have to calculate the number of atoms in 5.5 wt% Pb and 94.5 wt% of Sn.

As, 207.2 g of lead contains $6.022\times 10^{23}$ atoms

So, 5.5 g of lead contains $\frac{5.5}{207.2}\times 6.022\times 10^{23}=1.59\times 10^{22}$ atoms

and,

As, 118.71 g of lead contains $6.022\times 10^{23}$ atoms

So, 94.5 g of lead contains $\frac{94.5}{118.71}\times 6.022\times 10^{23}=4.79\times 10^{23}$ atoms

Now we have to calculate the percent composition of Pb and Sn in atom.

$\% \text{Composition of Pb}=\frac{\text{Atoms of Pb}}{\text{Atoms of Pb}+\text{Atoms of Sn}}\times 100$

$\% \text{Composition of Pb}=\frac{1.59\times 10^{22}}{(1.59\times 10^{22})+(4.79\times 10^{23})}\times 100=3.21\%$

and,

$\% \text{Composition of Sn}=\frac{\text{Atoms of Sn}}{\text{Atoms of Pb}+\text{Atoms of Sn}}\times 100$

$\% \text{Composition of Sn}=\frac{4.79\times 10^{23}}{(1.59\times 10^{22})+(4.79\times 10^{23})}\times 100=96.8\%$

Thus, the percent composition of Pb and Sn in atom is, 3.21 % and 96.8 % respectively.

6 0

3 years ago

10 points. Please help.

ratelena [41]

Answer:

-191.7°C

Explanation:

P . V = n . R . T

That's the Ideal Gases Law. It can be useful to solve the question.

We replace data:

2.5 atm . 8 L = 3 mol . 0.082 L.atm/mol.K . T°

(2.5 atm . 8 L) / (3 mol . 0.082 L.atm/mol.K) = T°

T° = 81.3 K

We convert T° from K to C°

81.3K - 273 = -191.7°C

6 0

3 years ago

Read 2 more answers

How would the moon appear from earth if the moon did not rotate?

ivolga24 [154]

If the moon did not rotate we would see all hemispheres of the moon as it revolves around the Earth and not just the phases.

4 0

3 years ago