All categories

4 years ago

Which of the samples described below contains the FEWEST atoms? No calculation is needed to answer this question.

Chemistry

1 answer:

Monica [59]4 years ago

6 0

Hello!

To do this, use the molar mass. This is how much a mole of an atom weighs. A mole is 6.02214076×10²³ atoms.

Molar masses of:

Se: 78.96 g/mol

Cu: 63.546 g/mol

Ba: 137.327 g/mol

Now, the element with the highest molar mass will have the fewest atoms. This is because the element weighs more, so therefore for the same amount of mass, there will be less of the element needed to reach that mass.

Therefore, 10g of Ba would have the fewest number of atoms.

Hope this helps!

You might be interested in

What does vinegar do to eggs

andre [41]

Eggshells are made primarily of calcium carbonate. The acid in vinegar softens the calcium of the eggshell. Adding a little vinegar to the water when boiling eggs is an old cook’s trick that makes them easier to peel.

A link to this experiment is below in the comment box

7 0

3 years ago

Mercury(II) oxide (HgO) decomposes to form mercury (Hg) and oxygen (O2). The balanced chemical equation is shown below.

IceJOKER [234]

2HgO=2Hg + O2
433,18 g. = 32 g
x. = 250 g
x= 3 384,21875 g of HgO is needed

4 0

3 years ago

How many grams are in 3.14 moles of PI₃?

OverLord2011 [107]

Answer:

$\boxed {\boxed {\sf 1290 \ g \ PI_3}}$

Explanation:

We want to convert from moles to grams, so we must use the molar mass.

<h3>1. Molar Mass</h3>

The molar mass is the mass of 1 mole of a substance. It is the same as the atomic masses on the Periodic Table, but the units are grams per mole (g/mol) instead of atomic mass units (amu).

We are given the compound PI₃ or phosphorus triiodide. Look up the molar masses of the individual elements.

Phosphorus (P): 30.973762 g/mol
Iodine (I): 126.9045 g/mol

Note that there is a subscript of 3 after the I in the formula. This means there are 3 moles of iodine in 1 mole of the compound PI₃. We should multiply iodine's molar mass by 3, then add phosphorus's molar mass.

I₃: 126.9045 * 3=380.7135 g/mol

PI₃: 30.973762 + 380.7135 = 411.687262 g/mol

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

Use the molar mass as a ratio.

$\frac {411.687262 \ g \ PI_3}{ 1 \ mol \ PI_3}$

We want to convert 3.14 moles to grams, so we multiply by that value.

$3.14 \ mol \ PI_3 *\frac {411.687262 \ g \ PI_3}{ 1 \ mol \ PI_3}$

The units of moles of PI₃ cancel.

$3.14 *\frac {411.687262 \ g \ PI_3}{ 1 }$

$1292.698 \ g\ PI_3$

<h3>3. Round</h3>

The original measurement of moles has 3 significant figures, so our answer must have the same. For the number we calculated, that is the tens place.

1292.698

The 2 in the ones place tells us to leave the 9.

$1290 \ g \ PI_3$

3.14 moles of phosphorous triiodide is approximately equal to <u>1290 grams of phosphorus triodide.</u>

4 0

3 years ago

What is the oxidation number of each phosphorus atom in H4P2O7

nekit [7.7K]

Answer:

Explanation:

The oxidation number of phosphorus can be obtained as follows:

H4P2O7 = 0

4(+1) + 2P + 7(—2) = 0

4 + 2P —14 = 0

Collect like terms

2P = 14 — 4

2P = 10

Divide both side by 2

P = 10/2

P = +5

The oxidation number of phosphorus is +5

7 0

4 years ago

Question 2*

Paraphin [41]

Answer:

Sc(OH)₃ = 96 g/mol

Explanation:

Gram formula mass:

Gram formula mass is the atomic mass of one mole of any substance.

It can be calculated by adding the mass of each atoms present in substance.

Sc(OH)₃:

Atomic mass of Sc = 45 amu

Atomic mas of O = 16 amu

There are three atoms of O = 16 ×3

Atomic mas of H = 1 amu

There are three atoms of H = 1 ×3

Gram formula mass of Sc(OH)₃:

Sc(OH)₃ = 45 ×1 + 16 ×3 + 1 ×3

Sc(OH)₃ = 96 g/mol

6 0

3 years ago