Complete the following table based on known properties of ionic and covalent compounds.

The rate constant for a certain reaction is measured at two different temperatures:

Talja [164]

Answer: The activation energy Ea for this reaction is 22689.8 J/mol

Explanation:

According to Arrhenius equation with change in temperature, the formula is as follows.

$ln \frac{k_{2}}{k_{1}} = \frac{-E_{a}}{R}[\frac{1}{T_{2}} - \frac{1}{T_{1}}]$

$k_1$ = rate constant at temperature $T_1$ = $2.3\times 10^8$

$k_2$ = rate constant at temperature $T_2$ = $4.8\times 10^8$

$E_a$ = activation energy = ?

R= gas constant = 8.314 J/kmol

$T_1$ = temperature = $280.0^0C=(273+280)=553K$

$T_2$ = temperature = $376.0^0C=(273+376)=649K$

Putting in the values ::

$ln \frac{4.8\times 10^8}{2.3\times 10^8} = \frac{-E_{a}}{8.314}[\frac{1}{649} - \frac{1}{553}]$

$E_a=22689.8J/mol$

The activation energy Ea for this reaction is 22689.8 J/mol

3 0

3 years ago

Draw the structures of all monobromo derivatives of pentane, c5h11br, which contain a 4-carbon chain.

SVETLANKA909090 [29]

Two or more compounds that have same molecular formula but differ in the arrangement of atoms in molecule and thus posses different properties are known as isomers.

The molecular formula of pentane is $C_5H_1_2$ substituting one hydrogen from pentane with bromine results in the formation of monobromo derivatives of pentane having molecular formula, $C_5H_1_1Br$ .

The structure of monobromo derivatives of pentane that is 1-bromopentane, 2-bromopentane, and 3-bromopentane and having molecular formula, $C_5H_1_1Br$ is shown in the image.

The other two arrangements of monobromo derivatives of pentane that is 2-bromo-2-methylbutane and 2-bromo-3-methylbutane is shown in the image.

There are different structures of monobromo derivatives of pentane having molecular formula, $C_5H_1_1Br$ which contain a 4-carbon chain are 1- bromo-2-methylbutane and 1-bromo-3-methylbutane shown in the image.

5 0

3 years ago

Which is the larger quantity 1.0 km or 1.0 mi

Norma-Jean [14]

A mile.

For reference, it's about 1,607 or so meters, and 1km is 1,000.

4 0

3 years ago

Read 2 more answers

1. A sample of polystyrene is found to have a number-average molar mass of 89,440 g mol−1 . Neglecting contributions from end gr

Snowcat [4.5K]

Answer:

The weight-average molar mass of polystyrene is 134,160 g/mol.

Explanation:

Molar mass of the monomer styrene , $C_8H_8$ , M=104 g/mol

Given , number average molar mass of the polymer , M'= 89,440 g/mol

Degree of polymerization = n

$n=\frac{M'}{M}=\frac{89,440 g/mol}{104 g/mol}=860$

The weight-average molar mass = $M_{avg}=?$

Molar mass dispersity is ratio of weight-average molar mass to the number average molar mass of the polymer.

$\text{Molar mass dispersity}=\frac{M_{avg}}{M'}$

$1.5=\frac{M_{avg}}{89,440 g/mol}$

$M_{avg}=89,440 g/mol\times 1.5 = 134,160 g/mol$

The weight-average molar mass of polystyrene is 134,160 g/mol.

8 0

3 years ago

A sample of oxide iron weighing 2.40g was heated in a stream of hydrogen until it was completely converted to the metal. If the

wlad13 [49]

Answer:

Fe₂O₃

Explanation:

To solve this question we must find the moles of Iron in 1.68g. With the difference of the masses we can find the moles of oxygen. The formula will be obtained with the ratio of both amount of moles:

<em>Moles Fe:</em>

1.68g * (1mol / 56g) =0.03moles

<em>Moles O:</em>

2.40g-1.68g = 0.72g * (1mol/16g) = 0.045moles

The ratio O/Fe is:

0.045moles / 0.03moles = 1.5 moles. this ratio is obtained if the formula is:

4 0

3 years ago