Choose all the correct answers.

For each pair of covalently bonded atoms, choose the one expected to have the shortest bond length. (A) C-I (B) H-I ...... (A,B)

UNO [17]

Answer:

i) B

ii) D

Explanation:

Bond length is determined by the size of the atoms involved and the bond order

A) C-I

B) H-I

answer : H-I has the shortest bond length because H has an electronegativity value of 2.2 while C has an electronegativity value of 2.5 hence the bond between H-I is greater than C - I due the electronegativity difference between H-I is greater as well.

C) H-Cl

D) H-I

answer : H-Cl has the shortest bond length due the electronegativity difference between H-CI is greater as well.

8 0

3 years ago

I need help with the question in the photo!!

Y_Kistochka [10]

Answer:

a semi-crystalline structure is formed, which holds the water molecules apart, making ice less dense than liquid water, such that it floats. This means that it insulates the water beneath, allowing organisms in the liquid water to survive. Cohesion is the tendency of molecules within a substance to ‘ stick together

explanation:

4 0

3 years ago

Read 2 more answers

A 5.325g sample of methyl benzoate, a compound in perfumes , was found to contain 3.758 g of carbon, 0.316 g of hydrogen, and 1.

Alexxandr [17]

Answer: The empirical and molecular formula of the compound is $C_4H_4O$ and $C_8H_8O_2$ respectively

Explanation:

We are given:

Mass of C = 3.758 g

Mass of H = 0.316 g

Mass of O = 1.251 g

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Carbon = $\frac{\text{Given mass of Carbon}}{\text{Molar mass of Carbon}}=\frac{3.758g}{12g/mole}=0.313moles$

Moles of Hydrogen = $\frac{\text{Given mass of Hydrogen}}{\text{Molar mass of Hydrogen}}=\frac{0.316g}{1g/mole}=0.316moles$

Moles of Oxygen = $\frac{\text{Given mass of oxygen}}{\text{Molar mass of oxygen}}=\frac{1.251g}{16g/mole}=0.078moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.078 moles.

For Carbon = $\frac{0.313}{0.078}=4.01\approx 4$

For Hydrogen = $\frac{0.316}{0.078}=4.05\approx 4$

For Oxygen = $\frac{0.078}{0.078}=1$

Step 3: Taking the mole ratio as their subscripts.

The ratio of C : H : O = 4 : 4 : 1

The empirical formula for the given compound is $C_4H_4O$

For determining the molecular formula, we need to determine the valency which is multiplied by each element to get the molecular formula.

The equation used to calculate the valency is:

$n=\frac{\text{Molecular mass}}{\text{Empirical mass}}$

We are given:

Mass of molecular formula = 130 g/mol

Mass of empirical formula = 68 g/mol

Putting values in above equation, we get:

$n=\frac{130g/mol}{68g/mol}=1.9\approx 2$

Multiplying this valency by the subscript of every element of empirical formula, we get:

$C_{(2\times 4)}H_{(2\times 4)}O_{(2\times 2)}=C_8H_8O_2$

Hence, the empirical and molecular formula of the compound is $C_4H_4O$ and $C_8H_8O_2$ respectively

4 0

3 years ago

n-Butane (C4H10) is burned with stoichiometric amount of oxygen. Determine the mole fraction of carbon dioxide and water in the

Fudgin [204]

Answer:

See details below

Explanation:

The balanced reaction equation is given below:

$2C_{4} H_{10}$ + $13O_{2}$ → $8CO_{2}$ + $10H_{2} O$

Mole fraction of CO2 to H20

= 8/10 = $\frac{4}{5}$

Mole ratio of C4H10 to CO2 is 2:8 = 1:4

1 mole of n-butane - 38.12 g

4 moles - ?

= 152.48g fuel consumed.

8 0

3 years ago

The following data is given to find the formula of a Hydrate:

umka21 [38]

The masses can be found by substractions:

Mass of CaSO₄.H2O (hydrate):

16.05 g - 13.56 g = 2.49 g

Mass of CaSO₄ anhydrate:

15.07 g - 13.56 g = 1.51 g

The mass of water is equal to the difference between the mass of the hydrate and the mass of the anhydrate:

2.49 g - 1.51 g = 0.98 g

The percent of water is found by the formula:

massWater ÷ massHydrate * 100%

0.98 g ÷ 2.49 g * 100% = 39.36%

The mole of water is calculated using water's molecular weight (18g/mol):

0.98 g ÷ 18 g/mol = 0.054 mol water

A similar procedure is made for the mole of salt (CaSO₄ = 136.14 g/mol)

1.51 g ÷ 136.14 g/mol = 0.011 mol CaSO₄

The ratio of mole of water to mole of anhydrate is:

0.054 mol water / 0.011 mol CaSO₄ = 0.49

In other words the molecular formula for the hydrate salt is CaSO₄·0.5H₂O

3 0

3 years ago