It is called permafrost :)
Answer:
D. 0.160
Explanation:
The solution A is obtained adding 2.0mL of a solution of bromocresol green, 5.0mL of 1.60M HAc and 2.0mL of a solution of KCl. The solution is diluted to 50mL
That means the HAc is diluted from 5.0mL to 50.0mL, that is:
50.0mL / 5.0mL = 10 times.
And the final concentration of HAc must be:
1.60M / 10 times =
0.160M
Right answer is:
<h3>D. 0.160</h3>
Answer:
C. Water passes into the salt solution, dehydrating bacterial cells and making them harmless.
Explanation:
The salt solution is hypertonic to the bacterial cells and as such, water molecules will move from the bacterial cells into the salt solution, dehydrating the cells and rendering them harmless.
Option A is also true but it is irrelevant to the question asked. Option B and D are wrong.
The correct option is C.
The oxidation state of Chromium chloride (III) is +3
How can we find the answer?
First of all write down what you know about the molecule:
1: The molecule hasn't got an electric charge (is not an ione), this means that either positive and negative charges of its atoms are balanced (we have the same number of positve and negative charges)
2: Since it's a salt, where the metal is chromium and the non metal is the alogen Chlorine, we know that the negative charge belogns to the non metal element because of its elettronegativity, therefore the positive charge belongs to the metale element (chromium).
3: when chlorin forms binary salts its oxidation state is always -1 (you can find out this info in a periodic table)
In <span>CrC<span>l3</span></span> we have 3 chlorine atoms where each of them carrys 1 negative charge, so the total amount of negative charges is -3
Since the charges are balanced, the question is: Which is the positive charge that Chromium must carry in order to balance 3 negative charges?
The answer comes out to +3
