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3 years ago

Which of the following is an example of an element? a brass b oxygen c rust d water

Chemistry

2 answers:

Anna [14]3 years ago

8 0

Answer:Water because it is an element

den301095 [7]3 years ago

3 0

Answer:

A) Oxygen

Explanation:

An element is defined as something made of only 1 type of atom. Brass and rust are made up of many types of atoms, and water has two types of atoms, hydrogen and oxygen. Oxygen is made up of two oxygen atoms, which are the same element. So, by definition, oxygen is an element.

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At 273 k and 1.00 x 10^-2 atm, the density of a gas is 1.24 x 10^-5 g/cm3.

bija089 [108]

Root mean square velocity is the square root of the mean of the squares of speeds of different molecules. From kinetic theory of gas, the formula of root mean square velocity=C $_{rms}$ = √ $\frac{3RT}{M}$ =√ $\frac{3PV}{M}$ =√ $\frac{3P}{d}$ , where, R= Universal gas constant, T= Absolute temperature, P= Pressure, V= Volume of gas, d= Density of gas.

Given, T=273 K, P=1.00 x 10⁻² atm, d=1.24 x 10⁻⁵ g/cm³.

(a) Using the formula $C_{rms}$ =√ $\frac{3P}{d}$ =√(3X1.00X10⁻²)/(1.24X10⁻⁵)=49.18

(b) Molar mass can be determined by using the formula $C_{rms}$ =√{3RT}{M}

49.18=√ $\frac{3X8.314X273}{M}$

49.18²=√(3X8.314X273)/M

M= $\frac{3X8.314X273}{49.18^{2} }$

M=1.67 ≅ 2

Molecular mass is 2.

8 0

3 years ago

Read 2 more answers

The density of aluminum is 2.70 g/cm'. If the volume of a piece of aluminum is 90.4 cm', what is

weeeeeb [17]

Answer:

33.4814814815

Explanation:

90.4/2.70

6 0

3 years ago

Which one of the following groups of chemical compounds is composed entirely of organic compounds?

guajiro [1.7K]

Answer:

Explanation:

Organic compounds are chemical compounds which usually contains one or more atoms of carbon, hydrogen, oxygen and sometimes nitrogen or sulphur. Carbon and hydrogen are the main element that is contained in most organic compounds.

Option A is wrong because calcium phosphate is not an organic compound, although all the other compounds in the option are organic compounds.

Option B is wrong because calcium chloride is not an organic compound

Option C is wrong also as calcium sulphate is not an organic compound

Option D is correct as all are organic compounds

7 0

3 years ago

SO2(g) + NO2(g) ↔ SO3(g) + NO(g) Kc = 0.33 A reaction mixture contains 0.41 M SO2, 0.14 M NO2, 0.12 M SO3 and 0.14 M NO. Which o

stepladder [879]

Answer:

The reaction will shift in the direction of products.

Explanation:

Step 1: Data given

A reaction mixture contains:

0.41 M SO2

0.14 M NO2

0.12 M SO3

0.14 M NO

Step 2: The balanced equation

O2(g) + NO2(g) ↔ SO3(g) + NO(g) Kc = 0.33

Step 3: Define the direction of the shift of reaction:

When Q<K, there are more reactants than products. As a result, some of the reactants will become products, causing the reaction to shift to the right.

When Q>K, there are more products than reactants. To decrease the amount of products, the reaction will shift to the left and produce more reactants.

When Q=K, the system is at equilibrium and there is no shift to either the left or the right.

Step 4: Calculate Q

Q = [NO][SO3]/[SO2][NO2]

Q = (0.14 *0.12)/(0.41*0.14)

Q = 0.0168/0.0574

Q = 0.293

Q<Kc

This means there are more reactants than products. Thud, some of the reactants will become products, causing the reaction to shift to the right.

The reaction will shift in the direction of products.

8 0

3 years ago

Use the balanced equation from number four above to determine the limiting reactant if we had a mixture of 5.0 moles of Fe and 4

Tom [10]

Answer:

2Fe + 3O₂ → 2Fe₂O₃

Limiting reactant: O₂

2Fe + O₂ → 2FeO

Limiting reactant: Fe

Explanation:

2Fe + 3O₂ → 2Fe₂O₃

2Fe + O₂ → 2FeO

These are the possible reactions:

In first case, 2 moles of Fe need 3 mol of oyxgen to react

If I have 5 moles of Fe, I will need (5 .3)/2 = 7.5 moles of O₂

Then, the oxygen is my limiting ( I only have 4 moles)

3 moles of O₂ need 2 moles of Fe

If I have 4 moles of O₂, I will need (4 .2)/3 = 2.66 moles (I have 5)

Fe, is the reactant in excess.

For second case, 2 moles of Fe need 1 mol of O₂, to react.

If I have 5 moles of Fe, I will need ( 5 .1) / 2 =2.5 moles of O₂

I have 4 moles of oxygen, so now it is my excess.

1 mol of O₂ need 2 moles of Fe, to react

If I have 4 moles of O₂, I will need the double of amount, 8 moles of Fe.

I have 5 moles, then the Fe is my limtiing reactant.

8 0

3 years ago