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tino4ka555 [31]
3 years ago
14

Which is the atomic number of an atom that forms an ion with 18 electrons and a charge of 2+?

Chemistry
1 answer:
Anettt [7]3 years ago
5 0

Answer:

Calcium

Explanation:

It has 20 electrons to start, loses two to become Ca 2+, and is left with 18 electrons

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1. If you have 8.1 g CO₂ and 2.3 g H₂, which one is the limiting reactant. Show your work. 2. Calculate the theoretical yield of
ZanzabumX [31]

Answer:

2.95 g of CH₄

Explanation:

To start this, we determine the equation:

4H₂  + CO₂ →  CH₄  +  2H₂O

4 moles of hydrogen react to 1 mol of carbon dioxide in order to produce 1 mol of methane and 2 moles of water.

To determine the limiting reactant, we need to know the moles of each reactant.

8.1 g . 1 mol/ 44g = 0.184 moles of carbon dioxide

2.3 g . 1mol / 2g = 1.15 moles of hydrogen

4 moles of hydrogen react to 1 mol of CO₂

Then, 1.15 moles may react to (1.15 . 1) /4 = 0.2875 moles

We only have 0.184 moles of CO₂, so this is the limiting reactant. Not enough CO₂ to complete the 0.2875 moles that are needed.

Ratio is 1:1. 1 mol of CO₂ produces 1 mol of methane

Then, 0.184 moles of CO₂ will produce 0.184 moles of CH₄

We convert moles to mass: 0.184 mol . 16 g /mol = 2.95 g

7 0
3 years ago
How many grams of calcium chloride would you need to make 1 L of solution containing 5 ppm calcium (Ca)?
Tresset [83]

Explanation:

The given data is as follows.

           Volume = 1 L,    Concentration of Ca = 5 ppm or 5 mg/L

As 1 mg = 0.001 g so, 5 mg /L will be equal to 0.005 g/l. Molar mass of calcium is 40.078 g/mol.

Hence, calculate molarity of calcium as follows.

           Molarity of Ca = \frac{\text{given concentration}}{\text{molar mass}}

                                  = \frac{0.005 g/l}{40.078 g/mol}

         Molarity of Ca = 1.25 \times 10^{-4} M

Hence, molarity of CaCl_{2} is 1.25 \times 10^{-4} M. Since, volume is same so, moles of calcium chloride will be 1.25 \times 10^{-4} mol.

Thus, we can conclude that mass of CaCl_{2} will be as follows.

             1.25 \times 10^{-4} \times 110.984       (molar mass of CaCl_{2} = 110.984 g/mol)

               = 0.0138 g

Thus, we can conclude that mass of CaCl_{2} is 0.0138 g.

4 0
3 years ago
Be sure to answer all parts. the equilibrium constant (kp) for the reaction below is 4.40 at 2000. k. h2(g) + co2(g) ⇌ h2o(g) +
svetoff [14.1K]
When we have the balanced reaction equation is:

H2(g)  + CO2(g) ↔ H2O(g)  + CO (g)

a) first, to calculate ΔG° for the reaction: 

we will use this formula:

ΔG° = -RT㏑Kp

when R is R- rydberg constant = 8.314J/mol.K

and T is the temperature in Kelvin = 2000 K

and Kp = 4.4 

so, by substitution:

ΔG° = - 8.314 *2000 *㏑4.4

        = - 24624 J/mol = - 24.6 KJ/mol

b) to calculate ΔG so, we will use this formula:

ΔG = ΔG° + RT㏑Qp

So we need first, to get Qp from the reaction equation:

when Qp = P products / P reactants

                 =  PH2O*PCO / PH2 * PCO2

                 = (0.66 atm * 1.2 atm) / (0.25 * 0.78)

                 = 4.1 

so by substitution:

ΔG = -24624 + 8.314*2000*㏑4.1

      = -1162 J/mol = - 1.16 KJ/mol
7 0
4 years ago
Read 2 more answers
What is another name for a condensation reaction? what is another name for a condensation reaction? water formation catabolism d
gregori [183]
Condensation is a chemical reaction in which two molecules are combined together and as a product formed a large molecule. There is also loss of small molecules in the condensation reaction. And mostly the functional groups combined in the reaction.
The other name for a condensation reaction is dehydration. As there is loss of molecule in condensation reaction, when that molecule is water it is said to be dehydration.
3 0
4 years ago
Read 2 more answers
What number on the periodic table determines the number of electrons lost or gained?
Setler79 [48]

Group 1-lose 1; Group 2-lose 2; Group 13-lose 3; Group 16-gain 2; Group 17-gain 1; Group 18-gain 0
8 0
4 years ago
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