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2 years ago

14

6. if a cross country runner travels at a speed of 10 mph and he runs for 2 hours, how many miles will he have run at the end of

the 2 hours? calculating distance

1 answer:

storchak [24]2 years ago

5 0

Explanation:

distance = speed x time

distance = 10 x 2

distance = 20miles

hope that helps :)

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What will be the the net ionic equations for the following ones:- a) AgNO3 + KCl b) Ni(NO3)2 + Na2S c) CaCl2 + Na2CO3. 2) Write

Zielflug [23.3K]

In a) the final equation is AgNO3 + KCl = AgCl + KNO3, b) Ni(NO3)2 + Na2S = 2NaNO3 + NiS; c) CaCl2 + Na2CO3 = 2 NaCl + CaCO3. In 2) The total net equation is Ca 2+ + CO32- = CaCO3 (s).

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3 years ago

A river with a flow of 50 m3/s discharges into a lake with a volume of 15,000,000 m3. The river has a background pollutant conce

spin [16.1K]

Explanation:

The given data is as follows.

Volume of lake = $15 \times 10^{6} m^{3}$ = $15 \times 10^{6} m^{3} \times \frac{10^{3} liter}{1 m^{3}}$

Concentration of lake = 5.6 mg/l

Total amount of pollutant present in lake = $5.6 \times 15 \times 10^{9} mg$

= $84 \times 10^{9}$ mg

= $84 \times 10^{3}$ kg

Flow rate of river is 50 $m^{3} sec^{-1}$

Volume of water in 1 day = $50 \times 10^{3} \times 86400 liter$

= $432 \times 10^{7}$ liter

Concentration of river is calculated as 5.6 mg/l. Total amount of pollutants present in the lake are $2.9792 \times 10^{10} mg$ or $2.9792 \times 10^{4} kg$

Flow rate of sewage = $0.7 m^{3} sec^{-1}$

Volume of sewage water in 1 day = $6048 \times 10^{4}$ liter

Concentration of sewage = 300 mg/L

Total amount of pollutants = $1.8144 \times 10^{10} mg$ or $1.8144 \times 10^{4}kg$

Therefore, total concentration of lake after 1 day = $\frac{131936 \times 10^{6}}{1.938 \times 10^{10}}mg/ l$

= 6.8078 mg/l

$k_{D}$ = 0.2 per day

$L_{o}$ = 6.8078

Hence, $L_{liquid}$ = $L_{o}(1 - e^{-k_{D}t}$

$L_{liquid}$ = $6.8078 (1 - e^{-0.2 \times 1})$

= 1.234 mg/l

Hence, the remaining concentration = (6.8078 - 1.234) mg/l

= 5.6 mg/l

Thus, we can conclude that concentration leaving the lake one day after the pollutant is added is 5.6 mg/l.

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3 years ago

An endergonic reaction with a Δh and Δs can be changed into an exergonic reaction.

zheka24 [161]

Full question:

This question is incomplete, here it is completed:

An endergonic reaction with a ______ ∆H and a ______ ∆S can be changed into an exergonic reaction by decreasing the temperature.

Option A: negative, positive

Option B: negative, negative

Option C: positive, positive

Option D: positive, negative

Answer:

Option B: negative, negative

Explanation:

The change in free energy (ΔG) of a system for a constant-temperature process is

ΔG = ΔH - TΔS

free energy is the energy available to do work. Thus, if a particular reaction is accompanied by a release of usable energy (that is, <u>ΔG is negative</u><u>), it is said to be</u><u> exergonic</u>. On the other hand, if a reaction consumes energy (that is, <u>ΔG is positive</u><u>), it is said to be </u><u>endergonic</u>.

Looking at the equation, we can see that if ΔH is negative and ΔS is negative, then ΔG will be negative only when TΔS is smaller in magnitude than ΔH. This condition is met when T is small.

ΔG = ΔH - TΔS

- -

This means that the reaction proceeds spontaneously at low temperatures. At high temperatures, the reverse reaction becomes spontaneous. An example of that would be the following reaction:

NH₃(g) + HCl(g) → NH₄Cl(s)

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3 years ago

What is the name of the process plants use to make the energy (food) they need?

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The answer you looking for is D

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3 years ago

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Find the pH of a solution whose H concentration is 0.7 x 10-3.

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Answer: pH = 3.15

Explanation: Solved in the attached picture.

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2 years ago