A chemist determined the boiling point of c8h18 to be 124.1c the actual boiling point is 125.7 what is the percent error

The main reason that it's important to test only one variable at a time is so that

bonufazy [111]

D. quantitative data can be recorded.

7 0

3 years ago

Based on the sign of E cell, classify these reactions as spontaneous or non spontaneous as written.? assume standard conditions.

sammy [17]

A electrochemical reaction is said to be spontaneous, if $E^{0} cell is positive.$

Answer 1:
Consider reaction: Ni^2+ (aq) + S^2- (aq) ----> + Ni (s) + S (s)

The cell representation of above reaction is given by;
 $S^{2-}/S // Ni^{2+}/Ni$

Hence, $E^{0}cell = E^{0} Ni^{2+/Ni} - E^{0} S/S^{2-}$
we know that, ${E^{0} Ni^{2+}/Ni = -0.25 v$
and ${E^{0} S/ S^{2-} = -0.47 v$

Therefore, $E^{0} cell$ = - 0.25 - (-0.47) = 0.22 v

Since, $E^{0} cell$ is positive, hence cell reaction is spontaneous
.....................................................................................................................

Answer 2:
Consider reaction: Pb^2+ (aq) +H2 (g) ----> Pb (s) +2H^+ (aq)

The cell representation of above reaction is given by;
 $H_{2} / H^{+} // Pb^{2+} /Pb$

Hence, $E^{0}cell = E^{0} Pb/Pb^{2+} - E^{0} H_{2}/H^{+}$
we know that, ${E^{0} Pb^{2+}/Pb = -0.126 v$
and ${E^{0} H_{2}/ H^{+} = -0 v$

Therefore, $E^{0} cell$ = - 0.126 - 0 = -0.126 v

Since, $E^{0} cell$ is negative, hence cell reaction is non-spontaneous.

....................................................................................................................

Answer 3:
Consider reaction: 2Ag^+ (aq) + Cr(s) ---> 2 Ag (s) +Cr^2+ (aq)

The cell representation of above reaction is given by;
 $Cr/Cr^{2+} // Ag^{+}/Ag$

Hence, $E^{0}cell = E^{0} Ag^{+}/Ag - E^{0} Cr/Cr^{2+}$
we know that, ${E^{0} Ag^{+}/Ag = -0.22 v$
and ${E^{0} Cr/ Cr^{2+} = -0.913 v$

Therefore, $E^{0} cell$ = - 0.22 - (-0.913) = 0.693 v

Since, $E^{0} cell$ is positive, hence cell reaction is spontaneous

8 0

3 years ago

Read 2 more answers

What process is used to find technological solutions.

ad-work [718]

Step one Define the problem. Step two Generate alternative solutions. Step three Evaluate and select an a. Hope this helped you!

5 0

3 years ago

If one benzene molecule is placed in water, the total entropy of the water + benzene system:___________

valkas [14]

Answer:

d) increases

Explanation:

Benzene is an aromatic hydrocarbon which is obtained from the destructive distillation of coal. It is a colourless volatile liquid with a sweet smell. It boils ar 80° C (353 K) and freezes at 5°C (2278 K). It is insoluble in water but mixes in all proportions with ethanol, ethoxyethane and methylbenzene. The reason which benzene is insoluble in water is that benzene is a non-polar compound and water is polar, meanwhile only "like dissolves like". So, when the benzene molecule is placed in water. There will be distortion and disturbance between the benzene molecule and the water. Thus, the particle of each molecule will be distant from each other. This state results to change in the entropy of the system as the entropy of the system increases.

3 0

3 years ago

Name 2 ways plants reproduce. give an example of each way.

cluponka [151]

Plants can reproduce through either sexual or asexual means. Sexual reproduction involves pollination helped by wind and or insects. Asexual reproduction involves tubers, bulbs and runners known as rhizomes and stolons as well as cuttings taken by humans.

7 0

3 years ago