The change of energy from one form to another results in the _

Which describes the path of energy that a gas powered car uses to drive along a road?

harkovskaia [24]

Answer:

mechanical energy to electrical energy to light energy

4 0

3 years ago

I need a Help plz! It’s my final exam!

LekaFEV [45]

Um i think gold... i think?

7 0

2 years ago

Predict the sign of the entropy change, ΔS∘, for each of the reaction displayed.Drag the appropriate items to their respective b

Sonja [21]

Answer:

Ag+(aq)+Br−(aq)→AgBr(s) NEGATIVE

CaCO3(s)→CaO(s)+CO2(g)2 POSITIVE

NH3(g)→N2(g)+3H2(g) POSITIVE

2Na(s)+Cl2(g)→2NaCl(s) NEGATIVE

C3H8(g)+5O2(g)→3CO2(g) +4H2O(g) POSITIVE

I2(s)→I2(g) POSITIVE

Explanation:

We have to remember, to solve this problem, that the entropy of a gas is higher than that of a liquid which in turn is higher than the solid. Therefore, comparing the reactants and products look for changes in the state of reactants and products. We also have to look for the increase or decrease of moles of each state based on the balanced chemical reaction.

Ag+(aq)+Br−(aq)→AgBr(s)

The reaction product is a single solid and the the reactants were 2 species in solution. The change in entropy is negative.

CaCO3(s)→CaO(s)+CO2(g)2

Here we have a solid reactant and we have a solid product plus a gas product. The change in entropy is positive.

NH3(g)→N2(g)+3H2(g)

We have 4 mole gases as products starting from 1 mol reactant gas, the entropy has increased.

2Na(s)+Cl2(g)→2NaCl(s)

In this reaction 2 mol solid Na and 1 mol Cl₂ gas are converted into 2 mol solid NaCl, the entropy has decreased.

C3H8(g)+5O2(g)→3CO2(g) +4H2O(g)

The products are 7 mol of gas versus 6 mol of gas reactants and therefore entropy has increased.

I2(s)→I2(g)

1 mol solid I₂ goes into 1 mol gas making the change in the entropy higher.

4 0

3 years ago

The half-life of a first-order reaction is 13 min. If the initial concentration of reactant is 0.085 M, how long would it take u

olasank [31]

Answer: It will take 8.2 minutes until the concentration decreases to 0.055 M

Explanation:

The time after which 99.9% reactions gets completed is 40 minutes

Explanation:

Expression for rate law for first order kinetics is given by:

$t=\frac{2.303}{k}\log\frac{a}{a-x}$

where,

k = rate constant

t = age of sample

a = let initial amount of the reactant

a - x = amount left after decay process

a) for completion of half life:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

$t_{\frac{1}{2}}=\frac{0.693}{k}$

$k=\frac{0.693}{13min}=0.053min^{-1}$

b) Time taken for 0.085 M to decrease to 0.055 M

$t=\frac{2.303}{0.053}\log\frac{0.085}{0.055}$

$t=8.2min$

Thus it will take 8.2 minutes until the concentration decreases to 0.055 M

5 0

3 years ago

students calculated the circumference of a globe to be 60.0 cm. The actual circumference of the glide is 63 cm. The percent devi

Naily [24]

#2. Percent error (or deviation) is calculated as ((TV-EV)/EV))*100

6 0

3 years ago

Read 2 more answers

The change of energy from one form to another results in the __ of some heat.