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3 years ago

A sample of gold (Au) has a mass of 35.12 g. what is the moles of each element for AU?

1 answer:

5 0

To determine the number of moles(n) of a substance, divide its amount given in grams by the molar mass. The element in the problem is gold (Au) which has a molar mass of 196.97 grams per mole. The division is better illustrated below

n = 35.12 g / 196.97 grams per mole

The answer to the operation above is 0.1783 moles. Therefore, there are approximately 0.1783 moles of Au in 35.12 grams.

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Based in the rules of John Dalton, what is a possible hypothesis that could be tested in the Atomic Theory lab?

marshall27 [118]

After many experiments and many different approaches to the question, the scientist may be able to develop a theory. The theory explains why nature behaves in the way described by the natural law. It answers not only the original question, but also any other questions that were raised during the process. The theory also predicts the results of further experiments, which is how it is checked. Theories are not the end of the process.

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3 years ago

Read 2 more answers

How do you convert kilograms to pounds?

Maru [420]

Answer: (1 Kilogram = 2.20462 pounds) . There are 2.2046226218 lb in 1 kilogram. To convert kilograms to pounds, multiply your figure by 2.205 for an approximate result. 1 kilogram is also equal to 2 lb and 3.27396195 oz. Working out a rough estimate in your head for converting to pounds and ounces may be tricky - remember that there are 16 ounces in a pound.

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2 years ago

Draw the Lewis structure for the compound with the formula COCl2COCl2. Use lines to show bonding electrons.

stira [4]

Answer : The Lewis-dot structure of $COCl_2$ is shown below.

Explanation :

Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.

In the Lewis-dot structure the valance electrons are shown by 'dot'.

The given molecule is, $COCl_2$

As we know that carbon has '4' valence electrons, chlorine has '7' valence electron and oxygen has '6' valence electrons.

Therefore, the total number of valence electrons in $COCl_2$ = 1(4) + 2(7) + 1(6) = 24

According to Lewis-dot structure, there are 8 number of bonding electrons and 16 number of non-bonding electrons.

6 0

4 years ago

What is the coefficient for calcium oxide? CaO(s) + CO2(g) → CaCO3(s)

VARVARA [1.3K]

Answer:

The coefficient is 1

Explanation:

CaO(s) + CO2(g) -> CaCO3(s)

In the balanced equation, the coefficient for CaO is 1

The coefficient represents the number of moles of a compound in the stoichiometry of the reaction

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3 years ago

A radioisotope decays to give an alpha particle andPb-208.

oee [108]

Answer: The original element is $_{84}^{212}\textrm{Po}$

Explanation:

Alpha decay is defined as the process in which alpha particle is emitted. In this process, a heavier nuclei decays into a lighter nuclei. The alpha particle released carries a charge of +2 units.

The released alpha particle is also known as helium nucleus.

$_Z^A\textrm{X}\rightarrow _{Z-2}^{A-4}\textrm{Y}+_2^4\alpha$

For the given alpha decay process of an isotope:

$^{Z}_{A}\textrm{X}\rightarrow ^{208}_{82}\textrm{Pb}+_2^4\alpha$

To calculate A:

Total mass on reactant side = total mass on product side

A = 208 + 4

A = 212

To calculate Z:

Total atomic number on reactant side = total atomic number on product side

Z = 82 + 2

Z = 84

The isotopic symbol of unknown element is $_{84}^{212}\textrm{Po}$

Hence, the original element is $_{84}^{212}\textrm{Po}$

3 0

3 years ago