All categories

2 years ago

Please help! USATestprep K12

Chemistry

2 answers:

NeX [460]2 years ago

8 0

Answer:

its none above

Explanation:

food webs have arrows that show the flow of energy from one orhganism to the next

bar graphs have bars and numbers and diagrams have words and pictures so it D

ycow [4]2 years ago

6 0

Answer: C

Explanation:

You might be interested in

What is the concentration of H+ in 0.0025 M HClO4? What is the pH of the solution? What is the OH− concentration in the solution

alexandr402 [8]

Answer:

A. The concentration of H+ is 0.0025 M

B. The pH is 2.6

C. The concentration of OH- is 3.98x10^-12 M

Explanation:

We'll begin by writing the balanced

dissociation equation of HClO4. This is illustrated below:

HClO4 —> H+ + ClO4-

A. Determination of the concentration of H+ in 0.0025 M HClO4. This is illustrated below:

From the balanced equation above,

1 mole of HClO4 produced 1 mole of H+.

Therefore, 0.0025 M of HClO4 will also produce 0.0025 M of H+.

The concentration of H+ is 0.0025 M

B. Determination of the pH.

The pH of the solution can be obtained as follow:

The concentration of H+, [H+]

= 0.0025 M

pH =?

pH = - log [H+]

pH = - log 0.0025

pH = 2.6

C. Determination of the concentration of OH-

To obtain the concentration of OH-, we must first calculate the pOH of the solution. This is illustrated below:

pH + pOH = 14

pH = 2.6

pOH =?

pH + pOH = 14

2.6 + pOH = 14

Collect like terms

pOH = 14 - 2.6

pOH = 11.4

Now, we can calculate the concentration of the OH- as follow:

pOH = - Log [OH-]

pOH = 11.4

11.4 = - Log [OH-]

- 11.4 = log [OH-]

[OH-] = anti log (- 11.4)

[OH-] = 3.98x10^-12 M

8 0

3 years ago

How many molecules are present in each sample?8.55 mol SO2 :molecules SO2 0.603 mol CO :molecules CO a sample of NH3 containing

sineoko [7]

Answer:

- 5.15×10²⁴ molecules of sulfur dioxide

- 3.63×10²³ molecules of carbon monoxide

- 6.02×10²³ molecules of ammonia

Explanation:

We begin from the relation that 1 mol of molecules contains NA of molecules

NA = 6.02×10²³

Now, we make rules of three:

1 mol has 6.02×10²³ molecules, therefore:

8.55 moles of SO₂ must have (8.55 . NA) / 1 = 5.15×10²⁴ molecules of dioxide

0.603 moles of CO must have (0.603 . NA) / 1 = 3.63×10²³ molecules of monoxide

Avogadro's Number of molecules of NH₃ are 6.02×10²³ molecules of ammonia

3 0

2 years ago

Can you help me with my Chemistry homework please? Can you answer the blank ones? And number 20 please.

Anarel [89]

i just cant understand the question

please take a clear pic

7 0

3 years ago

Given the following equation, what is the correct form of the conversion factor needed to convert the number of moles O2 to the

jek_recluse [69]

Answer:

Option A says we have 4 moles of Fe for each 3 moles O2

This is correct For 3 moles of O2 consumed, we need 4 moles of Fe to be reacted

Explanation:

Step 1: Data given

Step 2: The balanced equation

4Fe + 3O2 → 2Fe2O3

Step 3: Calculate the mol ratio

For 3 moles O2 we'll have 4 moles Fe

Option A says we have 4 moles of Fe for each 3 moles O2

This is correct For 3 moles of O2 consumed, we need 4 moles of Fe to be reacted

Option b says we have 2 mole Fe2O3 for each 4 moles Fe

This doesnt say anything about O2. So doesn't apply for this question.

Option C says we have 4 moles of Fe for each 2 moles Fe2O3

This is the same as option B, so doesn't apply for this question.

Option D says for each 3 moles of O2 we have 2 Fe2O3

This is true, but doesn't say anything about Fe so doesn't apply here.

4 0

3 years ago

Read 2 more answers

If the change in Gibbs free energy for a process is positive, the corresponding change in entropy for the universe will be

Gnesinka [82]

If the change in Gibbs free energy for a process is positive, the corresponding change in entropy for the universe will be positive.

<h3>What is Gibbs free energy?</h3>

This is defined as the energy used by a substance involved in a chemical reaction.

The Gibbs free energy and entropy has a direct relationship which is why a positive gibbs free energy will result in a corresponding positive entropy.

Read more about Gibbs free energy here brainly.com/question/9179942

4 0

2 years ago