If a glass bottle breaks into thousands of tiny pieces what type of change occurs

Which of the following is NOT a unit energy? (select all that applies)

never [62]

Answer:

Kelvin, Celsius, Fahrenheit

Explanation:

See my other answer for an explanation.

4 0

3 years ago

Read 2 more answers

Which of the following reactions have a positive ΔSrxn? Check all that apply.

PolarNik [594]

Answer:

The reactions that have a positive ΔS rxn are the first and the fourth choices:

2A(g) + B(s) → 3C(g)

2A(g) + 2B(g) → 5C(g)

Explanation:

ΔS rxn is the change of entropy of the chemical reaction.

ΔS rxn = S after reaction - S before reaction.

Therefore, a positive ΔS rxn means that the entropy after the reaction is greater than the entropy before the reaction.

You may use some assumptions to predict whether a reaction will lead an increase or decrease of the entropy.

First, assume that all the non-shown conditions, such as temperature and pressure, are constant.

Under that assumption, and from the meaning of entropy as a measure of the disorder or randomness of a system you can predict the sign of the change of entropy.

2A(g) + B(s) → 3C(g)

1) The solid compounds, B(s) in this case, are very ordered and so they have low entropy.

2) Gas molecules are highly disordered (scattered), and the greater the number of molecules of the gas the larger the entropy, S).

Hence, since the product side shows 3 gas molecules and the reactant side shows 2 gas molecules and 1 solid molecule, you predict that the products have a larger entropy than the reactants, meaning an increase in entropy: ΔS rxn is positive.

2A(g) + B(g) → C(g)

Using the same reasoning, 3 gas molecules in the reactant side have more entropy than 1 molecule in the product side, and so the reaction leads to a decrease in the entropy: ΔS rxn is negative

A(g) + B(g) → C(g)

Again, 2 gas molecules in the reactant side have more entropy than 1 molecule in the product side, and so the reaction leads to a decrease in the entropy: ΔS rxn is negative

2A(g) + 2B(g) → 5C(g)

With the same reasoing, 5 molecules in the product side, lets you predict that will have more entropy than 4 molecules in the reactant side, and, the entropy will increase: ΔS rxn is positive.

6 0

3 years ago

Seasonal variation in Earth's climate are caused by

Ivahew [28]

B. Earth’s tilt

Earth’s tilt exposes different parts of the earth to varying degrees of sunlight throughout the year, causing seasons.

3 0

3 years ago

One of the students in lab decided to use two fractionating columns (one on top of the other) instead of just one. How would thi

Andrews [41]

Answer:

See detailed explanation.

Explanation:

Hello there!

In this case, according to the given description, it turns out possible for us to infer that the second fractionating column on top of the first one will favor the light product, in this case hexane as it has the lowest boiling point and molar mass; in such a way, we can tell the following:

a) The separation between hexane and heptane will be increased as a purer hexane-rich product will be obtained on the top of the second column.

b) Will be increased as well, because the second column will remove more heptane.

c) Also, more pure heptane will be obtained on the bottom of the two columns, yet the most favored yield will be that of hexane.

All of the aforementioned is possible due to the fact that the second column will remove the amount of heptane that could not be removed on the top of the first column by taking the vapor-liquid equilibrium further from the first column's maximum separation, which is known as distillation sequences.

Regards!

8 0

3 years ago

For the reaction N2 + 3H2 = 2NH3, if you have 2.00 moles of N2 and 4.00 moles of H2 : a. Identify the limiting reactant. _______

EastWind [94]

Answer:

The answer to your question is below

Explanation:

For the reaction N2 + 3H2 = 2NH3, if you have 2.00 moles of N2 and 4.00 moles of H2 : a. Identify the limiting reactant. ____________

N2 + 3H2 = 2NH3

1 mol 3 moles 2 moles

Given 2 moles 4 moles

Rule of three for N2

x = (2 x 3) / 1 = 6 mol of H2, it means that is needed 6 moles of H2 and there are only 4, so the limiting reactant is H2

b. How many moles of NH3 can be formed? ____________

rule of three

3 moles of H2 --------------------- 2 moles of NH3

4 moles of H2 --------------------- x

x = (4x2)/3 = 2.7 moles of NH3 are formed

c. How many moles of the excess reactant will remain? _________

x = (4 x 1) / 3 = 1.33

Excess reactant = 2 - 1.33 = 0.67 moles

5 0

3 years ago