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3 years ago

How many atoms are there in 5.699 g of cobalt, Co? Express your answer with the appropriate significant figures and unit.

1 answer:

6 0

5.824x10^22 atoms of cobalt are in 5.699 grams of cobalt. First, determine the number of moles of cobalt you have by dividing the mass of cobalt by the atomic weight of cobalt. So Atomic weight cobalt = 58.933195 Mole cobalt = 5.699 g / 58.933195 g/mol = 0.096702716 mol Now to determine the number of atoms, multiply by Avogadro's number. So 0.096702716 * 6.0221409x10^23 = 5.823574x10^22 Rounding to 4 significant figures, gives 5.824x10^22

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If 1. 3618 moles of AsF3 are allowed to react with 1. 0000 mole of C2Cl6, what would be the theoretical yield of AsCl3, in moles

VARVARA [1.3K]

Answer:

AsF3:C2CI6

4:3

1.3618 moles: 1.02135 moles(1.3618÷4×3)

C2CI6 is the limting reagent

So the number of moles for AsCI3 is 0.817 moles( number of moles of the limting reagant) ÷3 ×4 (according to ratio by balancing chemical equation)=1.09 moles(3 s.f.)

Balanced equation

4AsF3 + 3C2Cl6 → 4AsCl3 + 3C2Cl2F4

Use stoichiometry to calculate the moles of AsCl3 that can be produced by each reactant.

Multiply the moles of each reactant by the mole ratio between it and AsCl3 in the balanced equation, so that the moles of the reactant cancel, leaving moles of AsCl3.

Explanation:

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2 years ago

How can endothermic and exothermic reactions help others (society)

AnnZ [28]

Here try this presentation, it should help :)

https://prezi.com/6ofdo3fadl9a/exothermic-and-endothermic-reactions-in-everyday-life/

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3 years ago

What is diffusion and how does it work

shepuryov [24]

Diffusion is the net movement of particles from a hight concentration to a low one

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3 years ago

Read 2 more answers

How to round significant figures

marissa [1.9K]

Explanation:

To round to a significant figure:

look at the first non-zero digit if rounding to one significant figure
look at the digit after the first non-zero digit if rounding to two significant figures
draw a vertical line after the place value digit that is required
look at the next digit
if it's 5 or more, increase the previous digit by one
if it's 4 or less, keep the previous digit the same
fill any spaces to the right of the line with zeros, stopping at the decimal point if there is one

7 0

2 years ago

Read 2 more answers

A chemist performs the following reaction:

tester [92]

Answer:

9.17 g

Explanation:

1) Calculate mols of PCl5

PCl5 (aq) + 4H2O (l) ⟶ H3PO4 (aq) + 5HCl (aq)

Mass of PCl5: 26.5g

Molar Mass of PCl5 208.24g/mol

Mol of PCl5 = Mass PCl5 /Molar mass PCl5 = 26.5g / (208.24g/mol) = 0.127257011 mol

2) Calculate mols of water needed to react

Mols of H2O per 1 Mols of PCl5 = 4 (because 4 water is needed to Phosphorus pentachloride).

Mols of H2O = Mol of PCl5 * 4 = 0.127257011 * 4 = 0.509028044 mols

3) Calculate Grams of water needed to react

Mols of H2O = 0.509028044 mols

Molar Mass of H2O = 18.015 g/mol

Mass of H2O = Mols of H2O * Molar Mass of H2O

= 0.509028044 mols* 18.015 g/mol = 9.17014021 g

sf = 3

9.17 g

4 0

2 years ago