What is true about all matter?

Convert the composition of the following alloy from atom percent to weight percent (a) 44.9 at% of silver, (b) 46.3 at% of gold,

vesna_86 [32]

Answer:

Mass percentage of gold : 33.35%

Mass percentage of silver: 62.80%

Mass percentage of copper : 3.85%

Explanation:

$N=n\times N_A$

Where : N = Number of atoms

n = moles

$N_A=6.022\times 10^{23}$ = Avogadro number

Let the total atoms present in the alloy be 100.

Atom percentage of silver = 44.9%

Atoms of of silver = 44.9% of 100 atoms = 44.9

Atomic weight of silver = 107.87 g/mol

Mass of 44.9 silver atoms = 107.87 g/mol × 44.9 = 4,843.363 g/mol

Atom percentage of gold= 46.3%

Atoms of of gold = 46.3% of 100 atoms = 46.3

Atomic weight of gold = 196.97 g/mol

Mass of 44.9 gold atoms = 196.97 g/mol × 46.3 = 9,119.711 g/mol

Atom percentage of copper = 8.8 %

Atoms of of copper = 8.8% of 100 atoms = 8.8

Atomic weight of copper = 63.55 g/mol

Mass of 44.9 copper atoms = 63.55 g/mol × 8.8 = 559.24 g/mol

Total mass of an alloy :4,843.363 g/mol + 9,119.711 g/mol + 559.24 g/mol

Mass percentage of gold :

$\frac{4,843.363 g/mol}{4,843.363 g/mol + 9,119.711 g/mol + 559.24 g/mol}\times 100=33.35 \%$

Mass percentage of silver:

$\frac{9,119.711 g/mol}{4,843.363 g/mol + 9,119.711 g/mol + 559.24 g/mol}\times 100=62.80\%$

Mass percentage of copper :

$\frac{559.24 g/mol}{4,843.363 g/mol + 9,119.711 g/mol + 559.24 g/mol}\times 100=3.85\%$

7 0

3 years ago

PLEASE ANSWER I WILL MAKE BRAINLIEST!!!

tangare [24]

Using an example like Christmas lights, I would say yes because normally a lot of them would go out if one light is broken.

3 0

3 years ago

Read 2 more answers

Which will dissolve at the fastest rate?

Nezavi [6.7K]

I need help on this one too I think it might be (b)

7 0

3 years ago

A 1.0 mole sample of fluorine gas at 25 °C has an average molecular velocity of 415 m/s. What is the total KE of the gas sample?

Mariana [72]

The total kinetic energy of the gas sample is 3.3 KJ

<h3>What is kinetic energy? </h3>

This is the energy possessed by an object in motion. Mathematically, it can be expressed as:

KE = ½mv²

Where

KE is the kinetic energy
m is the mass
v is the velocity

<h3>How to determine the mass of the fluorine gas</h3>

Molar mass of fluorine gas = 38 g/mol
Mole of fluorine gas = 1 mole
Mass of fluorine gas = ?

Mass = mole × molar mass

Mass of fluorine gas = 1 × 38

Mass of fluorine gas = 38 g

<h3>How to determine the KE of the gas sample</h3>

Mass (m) = 38 g = 38 / 1000 = 0.038 Kg
Velocity (v) = 415 m/s
Kinetic energy (KE) =?

KE = ½mv²

KE = ½ × 0.038 × 415²

KE = 3272.275 J

Divide by 1000 to express in kilojoule

KE = 3272.275 / 1000

KE = 3.3 KJ

Learn more about energy:

brainly.com/question/10703928

#SPJ1

4 0

2 years ago

How many moles of CaCO3 are needed to react with 12.5 mol SO2

grandymaker [24]

<h3><u>Answer;</u></h3>

= 12.5 Moles of CaSO3

<h3><u>Explanation</u>;</h3>

The reaction between CaCO3 and SO2 is given by the equation.

CaCO3(s) + SO2(g) → CaSO3(aq) + CO2(g)

The mole ratio between CaCO3 and SO2 is 1 : 1;

1 mole of CaCO3 reacts with 1 mole SO2 to form CaSO3 and CO2

Therefore;

<em>12.5 moles of SO2 will require 12.5 moles of CaSO3</em>

7 0

3 years ago