2 years ago

25 points! Help please

Chemistry

2 answers:

masya89 [10]2 years ago

7 0

Answer:

phase change solid -> liquid

Sedbober [7]2 years ago

4 0

Answer:

I think its b

Explanation:

but I wouldn't depend on this answer

You might be interested in

The gas formed when coal is heated in the absence of air_____________

aleksandr82 [10.1K]

The anser is- Carbon dioxide

6 0

2 years ago

1. When an element has a positive charge :

natita [175]

Answer:

2) AAAAAA

1)BBBBBBBB

3) I think a or c

8 0

2 years ago

Which best describes the asteroid belt

harina [27]

i think that the answer is d. millions of small rocky objects

5 0

2 years ago

Read 2 more answers

Find the pH of a solution that has an H+ concentration of 2.5x10-3 M

Nastasia [14]

Answer:

The pH is 2, 60

Explanation:

The pH gives us an idea of the acidity or basicity of a solution. It is calculated as:

pH = -log (H +)= -log (2.5x10-3 )

7 0

2 years ago

A 0.2722 g sample of a pure carbonate, X n CO 3 ( s ) , was dissolved in 50.0 mL of 0.1200 M HCl ( aq ) . The excess HCl ( aq )

Alex73 [517]

Answer:

0.00369 moles of HCl react with carbonate.

Explanation:

Number of moles of HCl present initially = $\frac{0.1200}{1000}\times 50.0$ moles = 0.00600 moles

Neutralization reaction (back titration): $NaOH+HCl\rightarrow NaCl+H_{2}O$

According to above equation, 1 mol of NaOH reacts with 1 mol of 1 mol of HCl.

So, excess number of moles of HCl present = number of NaOH added for back titration = $\frac{0.0980}{1000}\times 23.60$ moles = 0.00231 moles

So, mole of HCl reacts with carbonate = (Number of moles of HCl present initially) - (excess number of moles of HCl present) = (0.00600 - 0.00231) moles = 0.00369 moles

Hence, 0.00369 moles of HCl react with carbonate.

3 0

2 years ago