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3 years ago

How many atoms are present in 3 moles of chromium?

2 answers:

5 0

1 mole chromium -------------- 6.02 x 10²³ atoms
3 moles chromium ------------ ( atoms chromium )

atoms chromium = 3 x ( 6.02 x 10²³) / 1

atoms chromium = 1.806 x 10²⁴ / 1

= <span>1.806 x 10²⁴ atoms of chromium

hope this helps!</span>

DENIUS [597]3 years ago

4 0

In any element or substance, one mole of the substance is equivalent to 6.022 x10^23 atoms per mole. This is expressed as the Avogadro's number which is useful in finding out the total number of atoms in a sample. In this case, we are given with 3 moles of chromium. this is equivalent to 1.8066 x1024 atoms

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I don’t know how to find area

mr_godi [17]

To find the area of something you have to multiply the length x the with x the height. Or if it gives to the base then you multiply the base x the height.

8 0

3 years ago

What is the % yield when 12g of Mg react with HCl to produce 0.2g of H2?

goblinko [34]

Answer:

The yield is 20 %.

Explanation:

Mg + 2 HCl → MgCl2 + H2

(12 g Mg) / (24.30506 g Mg/mol) x (1 mol H2 / 1 mol Mg) x (2.015894 g H2/mol) = 0.9953 g H2.

(0.2 g) / (0.9953 g) = 0.20 = 20% yield

5 0

3 years ago

What two terms are used to describe the temperature at which solids and liquids of the same substance exist at the same time?

Irina-Kira [14]

<span>The answer is melting and freezing point. At the melting point the solid and liquid stage occur in equilibrium. The melting point of a material hinge on pressure and is typically quantified at standard pressure. When measured as the temperature of the opposite alteration from liquid to solid, it is denoted as the freezing point.</span>

4 0

3 years ago

Irina18 [472]

Answer:

Hehehe :)

Interesting.

Phase 1.

Zinc heated in Air

2Zn + O₂ = 2ZnO

Zinc Oxide is formed.

SOLID A = (ZnO)ZINC OXIDE

Phase 2.

Zinc Oxide is heated with Powdered Magnesium.

magnesium would displace Zinc since its higher in the series.

ZnO + Mg = MgO + Zn

SOLID B + SOLID C = MgO(Magnesium Oxide) + Zn(Zinc metal)

At Phase 3...( 1st Aspect)

Both MgO and Zn can react with Dilute HCl.

Now the products required from the question are a "SOLUTION D" AND "GAS E".

When MgO reacts with Dilute HCl

The products are

MgO + 2HCl = MgCl₂ + H₂O

Now H₂O could be steam(gas) or Water :(

This is a little Uncertain.

But if we use Zn as the one reacting with Dilute HCl

We have

Zn + 2HCl = ZnCl₂ + H₂

Now I'll go with this cos H₂ is simply Hydrogen Gas.

SOLUTION D + GAS E = ZnCl₂(Zinc Chloride) + H₂(Hydrogen Gas)

2nd aspect of Phase 3 ( or denominator)

ELECTROLYSIS OF MOLTEN B

B = MgO

MOLTEN B = MOLTEN MAGNESIUM CHLORIDE.

From Electrolysis of MgO

Mg²⁺ + 2e- = Mg

2O²⁻ = O₂ + 2e⁻

Combining Both Equations.

Mg²⁺ + 2O²⁻ = 2Mg(ₛ) + O₂(g)

Magnesium is a Silvery Metal :)

and Oxygen is a Gas.

Wow!!!

So this automatically makes "SILVERY METAL F" AND "GAS G" TO BE MAGNESIUM AND OXYGEN RESPECTIVELY.

SILVERY METAL F = MAGNESIUM

SILVERY METAL F = MAGNESIUMGAS G = OXYGEN

All the way down to phase 5 now.

Hope you're with me?

Now CuSO₄ is added to Mixture of Mg and O₂. Oxygen would prolly escape into the atmosphere

Leaving Mg to react with CuSO₄

Mg + CuSO₄ = MgSO₄(aq) + Cu(s)

Copper when precipitated from solution sometimes has Brown Pink Color.

MgSO₄ is Solid.

Niceeeee

That's exactly what they need as the answer.

Automatically...

BROWN PINK SOLID H = COPPER(CU)

SOLUTION I = MgSO₄(MAGNESIUM SULPHATE)

Hope this Helps :)

Have a great day.

3 0

3 years ago

A tank contains 115 miles of neon gas. It has a pressure of 57 atm at a temperature of 45 c. Calculate the volume of the tank.

Elena-2011 [213]

Answer:

Volume occupied by Neon gas is 52.67 L

Explanation:

Using Ideal Gas Equation:

PV = nRT

where

P = pressure exerted by the gas = 57 atm

V = volume occupied = ?

n = number of moles = 115 moles

R = Ideal gas constant = 0.0821 L.atm/K.mol

(R value should be taken according to the units of Temperature,pressure, volume and mole)

T = Temperature = 45 + 273 = 318 K

(For temperature conversion from C to K add 273 to temperature:T + 273)

PV = nRT , So

$V = \frac{nRT}{P}$

Put values of T,P,n,R

$V = \frac{115\times 0.0821\times 318}{57}$

$V = \frac{3002.39}{57}$

V = 52.67 L

Volume occupied by 115 moles of Neon gas at 57 atm Pressure and 45 C temperature is 52.67 L

6 0

4 years ago