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2 years ago

3. What's the empirical formula of a molecule containing 18.7% lithium, 16.3% carbon, and 65.0% oxygen?

Chemistry

1 answer:

Hunter-Best [27]2 years ago

8 0

Answer:

Empirical formula is Li₂CO₃.

Explanation:

Percentage of oxygen= 65.0%

Percentage of lithium = 18.7%

Percentage of carbon= 16.3%

Empirical formula = ?

Solution:

Number of gram atoms of C = 16.3/12 = 1.4

Number of gram atoms of Li = 18.7/6.94 = 2.7

Number of gram atoms of O = 65.0/ 16 = 4.1

Atomic ratio:

Li : C : O

2.7/1.4 : 1.4/1.4 : 4.1/1.4

2 : 1 : 3

Li : C : O = 2 : 1 : 3

Empirical formula is Li₂CO₃.

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This problem handles boiling-point elevation, which means we will use the formula:

ΔT = Kb * m

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Knowing that benzene's boiling point is 80.1°C, we solve for m:

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We use the definition of molality to calculate the moles of azulene:

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Xmoles azulene = 4.87 x10⁻³ moles azulene

We use the mass and the moles of azulene to calculate its molecular weight:

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The actual molecular formula of azulene is C₁₀H₈.

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2 years ago

Which of the following is most likely a heavier stable nucleus? (select all that apply) Select all that apply: A nucleus with a

kvv77 [185]

The question is incomplete, the complete question is;

Which of the following is most likely a heavier stable nucleus? (select all that apply) Select all that apply: A nucleus with a neutron:proton ratio of 1.05 A nucleus with a A nucleus with a neutron:proton ratio of 1.49 The nucleus of Sb-123 A nucleus with a mass of 187 and an atomic number of 75

Answer:

A nucleus with a A nucleus with a neutron:proton ratio of 1.49

A nucleus with a mass of 187 and an atomic number of 75

Explanation:

The stability of a nucleus depends on the number of neutrons and protons present in the nucleus. For many low atomic number elements, the number of protons and number of neutrons are equal. This implies that the neutron/proton ratio = 1

Elements with higher atomic number tend to be more stable if they have a slight excess of neutrons as this reduces the repulsion between protons.

Generally, the belt of stability for chemical elements lie between and N/P ratio of 1 to an N/P ratio of 1.5.

Two options selected have an N/P ratio of 1.49 hence they are heavy stable elements.

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2 years ago

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musickatia [10]

Answer:

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Explanation:

Given parameters:

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$\frac{P_{1} V_{1} }{T_{1} } = \frac{P_{2} V_{2} }{T_{2} }$

P, V and T represents pressure, volume and temperature

1 and 2 delineates initial and final states

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Input the variables and solve for V₂

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Artyom0805 [142]

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2 years ago