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2 years ago

HELP ASAP PLEASE!!!

Chemistry

1 answer:

sveticcg [70]2 years ago

4 0

1. Pure substances cannot be separated into any other kinds of matter, while a mixture is a combination of two or more pure substances.

2. A pure substance has constant physical and chemical properties, while mixtures have varying physical and chemical properties (i.e., boiling point and melting point).

3. A pure substance is pure, while a mixture is impure.

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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, ΔG is negative), it is said to be exergonic. On the other hand, if a reaction consumes energy (that is, ΔG is positive), it is said to be endergonic.

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)

4 0

3 years ago

A 133.8-gram sample of bronze was 10.3% tin by mass. Determine the total mass of tin in the sample.

Kay [80]

You just need to multiply the total mass by the decimal value of the part that is tin. 133.8*0.103=13.8g (following the rules of significant figures).

6 0

3 years ago

How many moles are there in 2.30 x 1024 atoms of silver?

Sunny_sXe [5.5K]

Answer:

Step 1 should be convert atoms to moles (n). Step 2 should be convert moles (n) to mass (m).

Step 1

Use dimensional analysis to convert the number of atoms to moles.

1 mole atoms = 6.022 × 10²³ atoms

n(Ag) = 2.3 × 10²⁴ Ag atoms × (1 mol Ag/6.022 × 10²³ Ag atoms) = 3.8193 mol Ag

Step 2

Convert the moles of Ag to mass.

mass (m) = moles (n) × molar mass (M)

n(Ag) = 3.8193 mol Ag

M(Ag) = atomic weight on the periodic table in g/mol = 107.868 g Ag/mol Ag

m(Ag) = 3.8193 mol × 107.868 g/mol = 412 g Ag = 410 g Ag rounded to two significant figures

The mass of 2.3 × 10²⁴ Ag atoms is approximately 410 g.

Explanation:

5 0

3 years ago

4. The picture shows a full moon.

Anuta_ua [19.1K]

Answer:

A full moon occurs when the Moon appears as a complete circle in the sky.

Explanation:

- We see it as a full orb because the whole of the side of the Moon facing the Earth is lit up by the Sun's rays.

- The moon shows no visible light of its own, so we only see the parts of the moon that are lit up by other objects.

6 0

2 years ago

Read 2 more answers

Help help help ASFAP

gulaghasi [49]

Answer:

A directory of relatives' phone numbers

Hope this helps

Explanation:

5 0

2 years ago