Potassium (K) and calcium fluoride (CaF2) can both be classified as<br> (Please help)

Electric current is the flow of particles with ________. a. Negative charge b. Positive charge c. Both positive and negative cha

Lelechka [254]

I believe Positive & Negative

4 0

2 years ago

Read 2 more answers

If 7.0 mol sample of a gas has a volume of 12.2 L, what would the volume be if the amount of gas was increased to 16.8 mol

Leviafan [203]

Answer:

$V_{2} = 29.28\,L$

Explanation:

Let assume that gas behaves ideally and experiments an isobaric and isothermal processes. The following relationship is applied to determined the final volume:

$\frac{V_{1}}{n_{1}} = \frac{V_{2}}{n_{2}}$

$V_{2} = V_{1} \cdot \left(\frac{n_{2}}{n_{1}} \right)$

$V_{2} = (12.2\,L)\cdot \left(\frac{16.8\,moles}{7\,moles} \right)$

$V_{2} = 29.28\,L$

5 0

3 years ago

What is the mass of 4.99×1021 platinum atoms?

charle [14.2K]

Answer:

$\boxed {\boxed {\sf 1.62 \ g \ Pt}}$

Explanation:

We are asked to find the mass of a number of platinum (Pt) atoms.

<h3>1. Convert Atoms to Moles </h3>

First, we convert atoms to moles using 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 platinum atoms.

We will convert using dimensional analysis so we set up a ratio using the information we know (6.022 × 10²³ platinum atoms in 1 mole of platinum).

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

We are converting 4.99 ×10²¹ atoms of Pt to moles of Pt, so we multiply by this value.

$4.99 \times 10^{21} \ atoms \ Pt *\frac {6.022 \times 10^{23} \ atoms \ Pt}{ 1 \ mol \ Pt}$

Flip the ratio so the units of atoms of platinum cancel.

$4.99 \times 10^{21} \ atoms \ Pt *\frac { 1 \ mol \ Pt}{6.022 \times 10^{23} \ atoms \ Pt}$

$4.99 \times 10^{21} *\frac { 1 \ mol \ Pt}{6.022 \times 10^{23}}$

$\frac { 4.99 \times 10^{21}}{6.022 \times 10^{23}} \ mol \ Pt$

Divide.

$0.008286283627 \ mol \ Pt$

<h3>2. Convert Moles to Grams </h3>

Next, we convert moles to grams using the molar mass. This is the mass of 1 mole of a substance. This is found on the Periodic Table because it is equivalent to the atomic mass, but the units are grams per mole instead of atomic mass units. Look up platinum's molar mass.

Pt: 195.08 g/mol

Set up another ratio using this new information (195.08 grams of Pt in 1 mole of Pt).

$\frac {195.08 \ g \ Pt}{ 1 \ mol \ Pt}$

Multiply by the number of moles we just calculated.

$0.008286283627 \ mol \ Pt*\frac {195.08 \ g \ Pt}{ 1 \ mol \ Pt}$

The units of moles of platinum cancel.

$0.008286283627*\frac {195.08 \ g \ Pt}{ 1 }$

$0.008286283627* {195.08 \ g \ Pt}$

$1.61648821\ g \ Pt$

<h3>3. Round</h3>

The original measurement of atoms ( 4.99 ×10²¹ ) has 3 significant figures, so our answer must have the same. For the number we found, that is the hundredth place. The 6 in the thousandth place tells us to round the 1 up to a 2.

$1.62 \ g \ Pt$

There are approximately <u>1.62 grams of platinum</u> in 4.99 ×10²¹ atoms of platinum.

8 0

2 years ago

How many atoms are in 0.3500 mol of gold

Vikentia [17]

8798076 atoms are in a 0.3500 mol of gold

3 0

3 years ago

If 30 grams of KCl is dissolved at 10°C, how many additional grams would be needed to make the solution saturated at 60°C? * Cap

MariettaO [177]

If 30 grams of KCl is dissolved at 10°C, 14 g of KCl should be added to make a saturated solution at 60 °C.

<h3>What is a saturated solution?</h3>

A saturated solution is a solution in which there is so much solute that if there was any more, it would not dissolve. Its concentration is the same as the solubility at that temperature.

Step 1. Calculate the mass of water.

At 10 °C, the solubility is 31.2 g KCl/100 g H₂O.

30 g KCl × 100 g H₂O/31.2 g KCl = 96 g H₂O

Step 2. Calculate the mass of KCl required to prepare a saturated solution at 60 °C.

At 60 °C, the solubility is 45.8 g KCl/100 g H₂O.

96 g H₂O × 45.8 g KCl/100 g H₂O = 44 g KCl

Step 3. Calculate the mass of KCl that must be added.

44 g - 30 g = 14 g

If 30 grams of KCl is dissolved at 10°C, 14 g of KCl should be added to make a saturated solution at 60 °C.

Learn more about saturated solutions here: brainly.com/question/24564260

6 0

1 year ago

Potassium (K) and calcium fluoride (CaF2) can both be classified as (Please help)