A gas effuses 4.0 times faster than oxygen (O2). What is the molecular mass of the gas?

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

Balance the equations by inserting coefficients as needed.

ASHA 777 [7]

Answer:

1. CaCO3 + 2HCl → CaCl2 + H2O + CO2

2. C6H12O2 + 8O2 → 6CO2 + 6H2O

Explanation:

7 0

3 years ago

Read 2 more answers

- La siguiente tabla, expone cómo desciende la temperatura (T) del aire con la altitud(h): Temperatura (ºC) 15 13,5 12 10,5 9 Al

Mrrafil [7]

Answer:

k = -0.006.

T₀ = 15 °C

Explanation:

Hola.

En este caso, considerando la gráfica mostrada en el archivo adjunto, podemos evidenciar que los datos dados se comportan de manera lineal, por lo que basado en la ecuación, T=k*h+To, podemos calcular la pendiente que basicamente es igual a k, tomando dos puntos en la gráfica:

$k=\frac{12-13.5}{750-500}=-0.0006$

Además, el valor de la temperatura inicial se puede extraer de la tabla, dado que esta es cuando la altura es 0 m, es decir 15 °C.

¡Saludos!

8 0

3 years ago

PLZ HELP!!! WILL GIVE BRAINLIEST!! Balance the following equations to show the law of conservation of mass: (10 points - 1 point

Dafna11 [192]

A - 1 CH4+ 1 O2 = 1 CO2+2 H2
b - 2 Al+3 Cl2 = 2 AlCl3
c - 1 CH2O+ 1 H2 = 1 CH3OH
*The ones that have the coefficient of 1 you can leave blank but if you have to put a number just put 1

4 0

3 years ago

Define the term hydrate

Salsk061 [2.6K]

Answer:

a compound,typically a crystalline one,in which water molecules are chemically bound to another compound or an element

3 0

2 years ago