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3 years ago

Can someone pleasee help me with this asap!! Im struggling

Chemistry

1 answer:

Alex777 [14]3 years ago

5 0

4a. D - The last number in the configuration represents the group, in this case 3, and the number of shells represent the period, which is also 3.

4bi. Rubidium metal reacts very rapidly with water to form a colourless solution of rubidium hydroxide (RbOH) and hydrogen gas (H2). The resulting solution is basic because of the dissolved hydroxide. The reaction is very exothermic and explosive.

4bii. Lithium is smaller in size than potassium . so valence electrons are more tightly held in Li than K. Due to larger size of K the valence electrons are loosely held and easy to remove the electron from K. Hence K is more reactive.

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Jane is sliding down a slide. What kind of motion is she demonstrating?

svp [43]

It is translational motion. i know because i found it on this site. its verified too, have a nice day

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3 years ago

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If 20.0 g LIOH react with excess KCl, giving a 17.0

adell [148]

The yield of lithium chloride is 1.92 grams.

Option D.

<h3>Explanation:</h3>

In this reaction, we can see that 1 mole of lithium hydroxide reacts with 1 mole of potassium chloride to produce 1 mole of lithium chloride and 1 mole of potassium hydroxide.

Molecular weight of lithium hydroxide is 24.

Molecular weight of lithium chloride is 42.5.

So 24 grams of lithium hydroxide produces 42.5 grams of lithium chloride.

So, 20 grams of lithium hydroxide produces $20 * 24 / 42.5$ grams =11. 29 grams of lithium chloride.

But this is when the yield is 100%.

But yield is 17%.

So the yield is 1.92 grams of lithium chloride.

8 0

3 years ago

How many carbon atoms are represented by the model below A) 0 B) 3 C) 2 D) 1

Bogdan [553]

Answer:

Option (B) 3.

Explanation:

In the model represented above, the two extreme represent carbon atoms since no other group are attached to it. The joint at the middle also represent carbon atom.

Thus, we can write a more simplify illustration for the model above as

C—C—C

From the above illustration, we can see that the model contains 3 carbon atom.

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3 years ago

FREÉ Points out!!!!!!!!!!!

Luda [366]

Answer:

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3 years ago

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A buffer solution contains 0.345 M acetic acid and 0.377 M sodium acetate . If 0.0613 moles of potassium hydroxide are added to

melamori03 [73]

Answer:

pH = 5.54

Explanation:

The pH of a buffer solution is given by the Henderson-Hasselbach (H-H) equation:

pH = pKa + log $\frac{[CH_3COO^-]}{[CH_3COOH]}$

For acetic acid, pKa = 4.75.

We calculate the original number of moles for acetic acid and acetate, using the given concentrations and volume:

CH₃COO⁻ ⇒ 0.377 M * 0.250 L = 0.0942 mol CH₃COO⁻

CH₃COOH ⇒ 0.345 M * 0.250 L = 0.0862 mol CH₃COOH

The number of CH₃COO⁻ moles will increase with the added moles of KOH while the number of CH₃COOH moles will decrease by the same amount.

Now we use the H-H equation to calculate the new pH, by using the new concentrations:

pH = 4.75 + log $\frac{(0.0942+0.0613)mol/0.250L}{(0.0862-0.0613)mol/0.250L}$ = 5.54

6 0

3 years ago