What rock has a hardness of 4,and has a dull luster. What is it?

What is the Gibbs energy, LaTeX: \Delta GΔ G, when the very first crystal of potassium nitrate forms in solution while cooling,

VARVARA [1.3K]

Answer:

74.344 kJ.

Explanation:

Below is an attachment containing the solution.

3 0

4 years ago

The direction of electrical force is based on the fact that like charges will___each other.

NeTakaya

Answer:

repel

Explanation:

When it comes to electrical forces, "opposites charges attract" while "like charges repel."

There are primarily two types of charges: positive charge and negative charge. The forces they exert upon each other will depend on their charges. The positive charge has an attractive force to a negative charge. On the contrary, it has a repulsive force to the same positive charge. Thus, it will repel each other.

So this means that opposite charges will draw closer together while like charges will move apart from each other.

7 0

3 years ago

Certain hydrocarbon is 92.3 % carbon and 7.7 % hydrogen by mass.If the molar mass of the hydrocarbon is approximately 40 g/mol,

zimovet [89]

Answer:

The hydrocarbon has a molecular formula of C3H3

Explanation:

Step 1: Data given

Suppose the mass of the compound is 100 grams

A hydrocarbon contains:

⇒ 92.3 % carbon = 92.3 grams

⇒ 7.7 % hydrogen = 7.7 grams

Molar mass of the compound is 40 g/mol

Molar mass of carbon = 12.01 g/mol

Molar mass of hydrogen = 1.01 g/mol

Step 2: Calculate moles

Moles = mass / molar mass

Moles carbon = 92.3 grams / 12.01 g/mol

Moles carbon = 7.69 moles

Moles hydrogen = 7.70 grams / 1.01 g/mol

Moles hydrogen = 7.62

Step 3: Calculate mol ratio

We divide by the smallest amount of moles

Carbon: 7.69/7.62 = 1

Hydrogen: 7.62/7.62 = 1

The empirical formula is CH

The molar mass is 13.02 g/mol

Step 4: Calculate the molecular formula

n = 40 g/mol / 13.02 g/mol

n ≈ 3

We need to multiply the empirical formula by 3 to get the molecular formula

Molecular formula = 3*(CH) = C3H3

The hydrocarbon is C3H3

5 0

3 years ago

All crystals have the same internal arrangement of atoms. a. True b. False

zhenek [66]

B - False. The crystals have the same internal arrangement of atoms in the same species. For example, all crystals of quartz (Onion, Amethyst, Citrine, Smoky) have the same trigonometrical arrangement.

the atoms in salt (NaCl) are arranged in a cubic way.

3 0

3 years ago

What happens to isotopes that are unstable?

Lesechka [4]

Explanation:

Isotopes are defined as the chemical species of the same element which differs in the number of neutrons. The isotopes which are unstable are known as radioactive isotope. A radioactive (unstable )isotope can undergo 3 decay process:

1. Alpha Decay: In this decay process, a larger nuclei decays into smaller nuclei by releasing alpha particle. The particle released has a charge of +2 and a mass of 4 units.

$_Z^A\textrm{X}\rightarrow _{Z-2}^{A-4}Y+_2^4\alpha$

2. Beta-minus decay: In this decay process, a neutron gets converted into a proton and an electron. the particle released during this process is a beta-particle.

$_Z^A\textrm{X}\rightarrow _{Z+1}^A\textrm{Y}+_{-1}^0\beta$

3. Beta-plus decay: In this decay process, a protons gets converted into a neutron and electron-neutrino particle. The particle released during this process is a positron particle.

$_Z^A\textrm{X}\rightarrow _{Z-1}^A\textrm{Y}+_{+1}^0\beta$

Isotopes which are unstable in nature can undergo these 3 decay processes.

5 0

3 years ago