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2 years ago

Ca(s)+br2(l)⟶cabr2(s) express your answer as a chemical equation. identify all of the phases in your answer.

1 answer:

3 0

The question requires to balance the equation.

The equation is already balanced, so the answer is:

Ca(s)+Br2(l)⟶CaBr2(s)


Explanation:


1) The phases are identified with a letter to the right of the compound or element:


So, for Ca, the phase is (s) which means solid.


For Br₂ (l) the phase is (l) which means liquid.


For CaBr₂(s) the phase is (s) which means solid.


2) The core work of balancing is make the number of atoms of each element on the reactants equal to the same number of atoms on the products side.


That is the law of conservation of mass applied to chemcial reactions.


3) So, you have to add coefficientes on the right place to make the number of atoms on the left side equal to the number of the same kind of atom on the right side.


In this table you can verify that the equation given is balanced:


atom left side right side

Ca 1 1

Br 2 2

So, you do not need to modify any coefficients.

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dsp73

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3 years ago

Trimix 10/50 is a gas mixture that contians 10% oxygen and 50% helium, and the rest is nitrogen. If a tank of trimix 10/50 has a

Nataly_w [17]

Answer: 1.61 x 10⁴ kPa

Dalton's law states that the sum of the partial pressures of each gas equals the total pressure of the gas mixture. According to this law,

Pi = xi P

where Pi is the partial pressure of the gas i, xi is the mole fraction of the gas i in the gas mixture and P is the total pressure.

The mole fraction is defined as the quotient between the moles of solute (ni) and the total moles of the mixture (nt), which is calculated by adding the moles of all its components:

xi = $\frac{n_{i} }{n_{t} }$

In the Trimix 10/50 mix you have 10% oxygen, 50% helium and 40% nitrogen.

To calculate the total number of moles of the mixture and thus determine the molar fraction of helium, we consider 100 g and calculate the number of moles that represent 10 g of O₂ (n₁), 50 g of He (n₂) and 40 g of N₂ (n₃):

n₁ = 10 g x $\frac{1 mol}{31.998 g}$ = 0.313 mol

n₂ = 50 g x $\frac{1 mol}{8.005 g}$ = 6.246 mol

n₃ = 40 g x $\frac{1 mol}{28.013 g}$ = 1.428 mol

Then the total number of moles (nt) will be:

nt = n₁ + n₂ + n₃ = 0.313 mol + 6.246 mol +1.428 mol

nt = 7,987 mol

Then, the mole fraction of helium (x₂) in the mixture will be,

x₂ = $\frac{6.246 mol}{7.987 mol}$ = 0.78

and the partial pressure of helium in the mixture, according to Dalton's law, will be:

P₂ = x₂ P = 0.78 x 2.07 x 10⁴ kPa

P₂= 1.61 x 10⁴ kPa

So, the partial pressure of helium if a tank of trimix 10/50 has a total pressure of 2.07 x 104 kPa is 1.61 x 10⁴ kPa

5 0

3 years ago

What best explains the type of energy present in the vibrating atoms of a substance

luda_lava [24]

The type of energy present in the vibrating atoms of a substance is a thermal energy and it is a kinetic type of energy. It is associated with movement within the crystal lattice of substance. ... Eventually, it can lead to motion of the atoms which is a form of kinetic energy.

7 0

2 years ago

Gold is alloyed (mixed) with other metals to increase its hardness in making jewelry.

KiRa [710]

Answer:

A) 54.04%

B) 13-karat

Explanation:

A) From the problem we have

1) Mg + Ms = 9.40 g

2) Vg + Vs = 0.675 cm³

Where M stands for mass, V stands for volume, and g and s stand for gold and silver respectively.

We can rewrite the first equation using the density values:

3) Vg * 19.3 g/cm³ + Vs * 10.5 g/cm³ = 9.40

So now we have a system of two equations (2 and 3) with two unknowns:

We express Vg in terms of Vs:

Vg + Vs = 0.675 cm³

Vg = 0.675 - Vs

We replace the value of Vg in equation 3:

Vg * 19.3 + Vs * 10.5 = 9.40

(0.675-Vs) * 19.3 + Vs * 10.5 = 9.40

13.0275 - 19.3Vs + 10.5Vs = 9.40

-8.8 Vs + 13.0275 = 9.40

Vs = 0.412 cm³

Now we calculate Vg:

Vg + Vs = 0.675 cm³

Vg + 0.412 cm³ = 0.675 cm³

Vg = 0.263 cm³

We calculate Mg from Vg:

0.263 cm³ * 19.3 g/cm³ = 5.08 g

We calculate the mass percentage of gold:

5.08 / 9.40 * 100% = 54.04%

We multiply 24 by the percentage fraction:

24 * 54.04/100 = 12.97-karat ≅ 13-karat

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2 years ago

What is the measure of the efficiency of a chemical reaction? percent yield annual yield actual yield theoretical yield

artcher [175]

Answer:

Precent yield

Explanation:

This is takes into account how much of a substance should have been created (theoretical yield) and compares it to what was actually created (the actual yield).

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3 years ago