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3 years ago

Need help on this question asap pleasee I would really appreciate it

Chemistry

1 answer:

Elza [17]3 years ago

6 0

Answer:

See Explanation

Explanation:

An endothermic reaction is one in which energy is absorbed and the change in enthalpy for the reaction is positive.

If we look at the reaction 2HgO + 45kcal ----> 2Hg + O2; we will notice that

i) 45kcal of energy was taken in (absorbed) for the reaction to occur

ii) The value of the reaction enthalpy is positive

For these two reasons, the reaction is an endothermic reaction as written.

You might be interested in

How many atoms are there in 5K2CO3

Dvinal [7]

Answer:

Depends on what are you refering to

Explanation:

So depending on what you are looking for (your question is quite vauge)

there are 5 atoms of the comopound (K2CO3)

within that compound, there are 2 atoms of Potassium and 1 atom of Carbonate. Within Carbonate there are 4 atoms (1 carbon and 3 oxygens)

so answers may be

5, 15, or 25.

I hope this helps.

4 0

2 years ago

Hey I have a chemistry problem pls tell me how do you find the percentage thx...

Julli [10]

Answer:

88.24

Explanation:

find the total mass of the compound using there RAM which has been give then the mass of caborn

4 0

3 years ago

A 100.0 ml sample of 0.10 m ca(oh)2 is titrated with 0.10 m hbr. determine the ph of the solution after the addition of 400.0 ml

WINSTONCH [101]

The balanced equation for the reaction is as follows;
Ca(OH)₂ + 2HBr --> CaBr₂ + 2H₂O
stoichiometry of Ca(OH)₂ to HBr is 1:2
number of Ca(OH)₂ moles reacted - 0.10 mol/L x 0.1000 L = 0.010 mol
Number of HBr moles added - 0.10 mol/L x 0.4000 = 0.040 mol
1 mol of Ca(OH)₂ needs 2 mol of HBr for neutralisation
therefore 0.010 mol of Ca(OH)₂ needs - 0.010 x 2 = 0.020 mol of HBr to be neutralised
but 0.040 mol of HBr has been added therefore number of moles of HBr in excess - 0.040 - 0.020 = 0.020 mol
then pH of the medium can be calculated using the excess H⁺ ions
HBr is a strong acid therefore complete ionization
[HBr] = [H⁺]
[H⁺] = 0.020 mol / (100.0 + 400.0 mL)
= 0.020 mol / 0.5 L
= 0.040 mol/L
pH = -log[H⁺]
pH = - log [0.040 M]
pH = 1.40
pH of the medium is 1.40

8 0

3 years ago

Will a parachute slow a skydiver more at a very high altitude or a lower altitude?

kompoz [17]

The answer is High altitude

5 0

3 years ago

A gas is contained in a cylinder with a volume of 2.9 L at a temperature of 32.7oC and a pressure of 645.3 torr. The gas is then

stealth61 [152]

Answer: 41 atm

Explanation:

Given that:

Original Volume of gas V1 = 2.9L

Temperature T1 = 32.7°C

Convert Celsius to Kelvin

(32.7°C + 273 = 305.7K)

Pressure P1 = 645.3 torr

New Volume V2 = 0.23 L

New temperature T2 = 894.7°C

Convert Celsius to Kelvin

(894.7°C + 273 = 1167.7K)

New pressure = ?

Then, apply the combined gas equation

(P1V1)/T1 = (P2V2)/T2

(645.3 torr x 2.9L)/305.7K = (P2 x 0.23L)/1167.7K

1871.37 / 305.7 = 0.23P2 / 1167.7

To get P2, Cross multiply

1871.37 x 1167.7 = 305.7 x 0.23P2

2185198.749 = 70.311P2

Divide both sides by 70.311

2185198.749/70.311 = 70.311P2/70.311

31079.045 torr = P2

Now, convert pressure in torr to atmosphere

Since 760 torr = 1 atm

31079.045 torr = Z

cross multiply

760 torr x Z = 31079.045 torr x 1 atm

Z = 31079.045 torr / 760 torr

Z = 40.89 atm (Round to the nearest whole number as 41 atm)

Thus, new pressure of gas is 41 atm

3 0

2 years ago