What is the correct name for ionic compound Cs2S?

Question 5 why does grinding solid crystals increase the rate of dissolving for a solid solute in water? smaller crystals are mo

My name is Ann [436]

Grinding solid crystals increase the rate of dissolving for a solid solute in water because smaller crystals have more surface area. The solubility of a substance depends on the physical and chemical properties of the solute and solvent as well as the temperature, pressure and the pH of the solution. For example increase in temperature increases the rate at which a solute dissolves in a solvent.

5 0

3 years ago

How many atoms are there in 8.88 g Si?

Mariana [72]

Answer:

$\boxed {\boxed {\sf 1.90 \times 10^{23} \ atoms \ Si}}$

Explanation:

We are asked to find how many atoms are in 8.88 grams of silicon.

<h3>1. Grams to Moles </h3>

First, we convert grams to moles. We use the molar mass or the mass of 1 mole of a substance. These values are found on the Periodic Table as they are equal to the atomic masses, but the units are grams per mole instead of atomic mass units.

Look up silicon's molar mass.

Si: 28.085 g/mol

We will convert using dimensional analysis. Set up a conversion factor with the molar mass.

$\frac { 28.085 \ g \ Si}{1 \ mol \ Si}$

We are converting 8.88 grams of silicon to moles, so we multiply by this value.

$8.88 \ g \ Si *\frac { 28.085 \ g \ Si}{1 \ mol \ Si}$

Flip the fraction so the units of grams of silicon cancel.

$8.88 \ g \ Si *\frac{1 \ mol \ Si} { 28.085 \ g \ Si}$

$8.88 *\frac{1 \ mol \ Si} { 28.085 }$

$\frac {8.88} { 28.085 } \ mol \ Si$

$0.316183015845 \ mol \ Si$

<h3>2. Moles to Atoms </h3>

Next, we convert moles to atoms. We use Avogadro's Number or 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this case, the particles are atoms of silicon.

Set up another conversion factor.

$\frac {6.022 \times 10^{23} \ atoms \ Si}{1 \ mol \ Si}$

Multiply by the number of moles we calculated.

$0.316183015845\ mol \ Si *\frac {6.022 \times 10^{23} \ atoms \ Si}{1 \ mol \ Si}$

The units of moles of silicon cancel.

$0.316183015845 * \frac {6.022 \times 10^{23} \ atoms \ Si}{1}$

$0.316183015845 * {{6.022 \times 10^{23} \ atoms \ Si}$

$1.90405412 \times 10^{23} \ atoms \ Si$

<h3>3. Significant Figures</h3>

The original measurement of 8.88 grams has 3 significant figures, so our answer must have the same.

For the number we calculated, that is the hundredth place. The 4 in the thousandth place tells us to leave the 0 in the hundredth place.

$1.90 \times 10^{23} \ atoms \ Si$

<u>8.88 grams of silicon contains 1.90 ×10²³ atoms of silicon.</u>

6 0

3 years ago

In each of the following blanks, only enter a numerical value.

tatiyna

Answer:

1) 1,... 2

2) 18

3) n= 3 and I=1

Explanation:

1) when l= 0, its an s-sub-level, and only 1 orbital is possible which can carry only 2-electrons

2) the maximum number of electron is given by 2n^2= 2×3^2= 18

3) in 3p, the coefficient of p is the value of n= 3 and l-value of P is 1

5 0

2 years ago

For 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g), if you begin with 16.00 g ammonia and excess oxygen, how many grams of water will be ob

iragen [17]

12.7 grams approximately

8 0

3 years ago

What is the value of DeltaG in a spontaneous reaction

krok68 [10]

Gibbs free energy of a reaction ( Δ G ) is the change in free energy of a system that undergoes the chemical reaction. It is the energy associated with the reaction, which is available to do some useful work. If ΔG<0 , then the reaction can be utilized to do some useful work. If ΔG>0 , then work has to be done on the system or external energy is required to make the reaction happen. ΔG=0 when the reaction is at equilibrium and there is no net change taking place in the system.

6 0

3 years ago

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