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mixer [17]
2 years ago
15

How many moles are there in 3.9 grams of potassium

Chemistry
2 answers:
Maksim231197 [3]2 years ago
8 0

Answer:

0.0997 mol K

Explanation:

First of all, the picture and your question do NOT match so I will solve for what you are asking for.

3.9g x 1 mol/39.10 g = 0.0997 mol K

The 39.10 grams is the atomic mass of potassium

zimovet [89]2 years ago
7 0
1.77 so A. I don’t need to explain this just helping out haha
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Difference between emprical and molecular formula
Musya8 [376]

Answer:

The key difference between empirical and molecular formulas is that an empirical formula only gives the simplest ratio of atom whereas a molecular formula gives the exact number of each atom in a molecule.

3 0
2 years ago
You are making a 1L solution that you want to be buffered with ammonia and ammonium. However ammonia is a gas that is difficult
zloy xaker [14]

Answer:

54 grams ammonium chloride and 40 grams sodium hydroxide

Explanation:

A buffer is a solution that contains either a weak acid and its salt or a weak base and its salt, the solution is resistant to changes in pH. This means that, a buffer is an aqueous solution of either a weak acid and its conjugate base or a weak base and its conjugate acid.

A Buffer is used to maintain a stable pH in a solution, buffers can neutralize small quantities of additional acid of base. For any buffer solution, there is always a working pH range and a set amount of acid or base that can be neutralized before the pH will change. The amount of acid or base that can be added to a buffer before changing its pH is called its buffer capacity.

A good buffer mixture is supposed to have about equal concentrations of its both components. It is a rule of thumb therefore, that a buffer solution has generally lost its usefulness when one component of the buffer pair is less than about 10% of the other component.

The implication of this is that the ammonium chloride and sodium hydroxide should be of approximately the same concentration. If the masses are dissolved as shown in the answer, then we will have 1molL-1 of each component of the buffer in accordance with the rule of thumb stated above.

4 0
3 years ago
A student was assigned the task of determining the identity of an unknown liquid. The student weighed a clean, dry 250-mL Erlenm
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Answer:

248.4 mL

Explanation:

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Water = (Erlenmeyer + Water) - Erlenmeyer

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Water = 248.4 g

if the density of water is 1 g/mL, we can say that each mL of water weigh 1 g, so we have 248.4 mL of water in the Erlenmeyer Flask.

4 0
3 years ago
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Neko [114]

Answer:

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Explanation:

6 0
3 years ago
Which of the following elements is the most reactive?<br> A. At<br> B.Cl<br> C.I<br> D.Br
adell [148]

Answer:

B.  Cl.

Explanation:

These are Group  7 elements whose reactivity reduces as you go down the group. Chlorine  has a smaller atoms than the rest and has a stronger  tendency to grab an electron in its valency shell. This is because its nucleus is closer to the outer electrons than the other elements.

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