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3 years ago

Select the items that describe a chemical property below. Choose THREE correct answers.

Chemistry

1 answer:

FrozenT [24]3 years ago

8 0

Answer:

2:A handwarmer gets warm when it is opened and exposed to air.

3:Propane ignites to heat a grill.

4:Cotton is dyed red to make a dress.

Explanation:

The definition of a chemical property is when a property of characteristic of a substance that is <em><u>observed</u></em> during a reaction in which a chemical has been changed

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Using 18.8L, calculate the volume (in L) of water vapour that should be produced by the reaction of 35.0 g

victus00 [196]

Answer:

A. 18.8L

B. 75.2L of H2O.

Explanation:

A. Determination of the volume of 35g of C3H8.

Date obtained from the question include the following:

Mass of C3H8 = 35g

Temperature (T) = 40°C

Pressure (P) = 110KPa

Volume (V) =..?

Next, we shall determine the number of mole (n) in 35g of C3H8. This is illustrated below:

Molar mass of C3H8 = (3x12) + (8x1) = 44g/mol

Mass of C3H8 = 35g

Mole of C3H8 =..?

Mole = mass /molar mass

Mole of C3H8 = 35/44

Mole of C3H8 = 0.795 mole

Finally, we shall determine the volume of 35g of C3H8 as follow:

Temperature (T) = 40°C = 40°C + 273 = 313K

Pressure (P) = 110KPa

Number of mole (n) = 0.795 mole

Gas constant (R) = 8.314 KPa.L/Kmol

Volume (V) =..?

PV = nRT

110 x V = 0.795 x 8.314 x 313

Divide both side by 110

V = (0.795 x 8.314 x 313)/110

V = 18.8L

Therefore, the volume of 35g of C3H8 under the conditions given is 18.8L

B. Determination of the volume of water vapour produced by the reaction of 35g of propane, C3H8.

From the calculations made in (A) above, 35g of C3H8 is equivalent to 18.8L of C3H8.

Thus, we can obtain the volume of water vapour produced as follow:

C3H8 + 5O2 —> 3CO2 + 4H2O

From the balanced equation above,

1L of C3H8 reacted to produce 4L of H2O.

Therefore, 18.8L of C3H8 will react to produce = (18.8 x 4)/1 = 75.2L of H2O.

Therefore, 75.2L of H2O were produced from the reaction.

4 0

4 years ago

Calculate the decrease in temperarure when 2.00 L at 20.0 degrees celsius is compressed to 1.00 L.

Serga [27]

I suspect that the pressure of this change is constant therefore

The equation is used from the combined gas law. (When pressure is constant both P's will cancel out P/P = 1)
V/T = V/T
Initial Change

Initially we have 2L at 20 degress what temperature will be at 1L.

2/20 = 1/T
0.1 = 1/T
0.1T = 1
T = 1/0.1
T = 10 degress celsius.

Hope this helps if you won't be able to understand what is the combined gas law just tell me :).

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3 years ago

Drug testing of athletes and other individuals is big business.

ziro4ka [17]

Answer:

bioanalytical chemistry

Explanation:

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4 years ago

If the mass of 23 gummi bears is 49.2g, what is the average mass of one gummi bear? Round answer to the nearest 0.00g (do NOT ty

Mila [183]

just divide the mass 49.2 grams by the amount of gummi bears 23 to get the answer of 2.1391 then it says to round to 2 decimals so 2.14 grams

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3 years ago

For the reaction below, complete the rate expression that relates the change in concentration with respect to time to the rate o

Ann [662]

Answer: Rate in terms of disappearance of $NO$ = $-\frac{1d[NO]}{2dt}$

Rate in terms of disappearance of $Cl_2$ = $-\frac{1d[Cl_2]}{1dt}$

Rate in terms of appearance of $NOCl$ = $\frac{1d[NOCl]}{2dt}$

Explanation:

Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.

$2NO+Cl_2\rightarrow 2NOCl$

The rate in terms of reactants is given as negative as the concentration of reactants is decreasing with time whereas the rate in terms of products is given as positive as the concentration of products is increasing with time.

Rate in terms of disappearance of = $-\frac{1d[NO]}{2dt}$

Rate in terms of disappearance of = $-\frac{1d[Cl_2]}{1dt}$

Rate in terms of appearance of $NOCl$ = $+\frac{1d[NOCl]}{2dt}$

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3 years ago