7. The youngest part of the ocean floor is found ___

A sample of milk kept at 25 °C is found to sour 40 times as rapidly as when it is kept at 4 °C. Estimate the activation energy f

irga5000 [103]

Answer:

120.575 kJ is the activation energy for the souring process.

Explanation:

The formula for an activation energy is given as:

$\log (\frac{K_2}{K_1})=\frac{Ea}{2.303\times R}[\frac{1}{T_1}-\frac{1}{T_2}]$

where,

$K_1$ = rate constant at $25^oC$ = $40k$

$K_2$ = rate constant at $4^oC$ = $k$

$Ea$ = activation energy for the reaction = ?

R = gas constant = 8.314 J/mole.K

$T_1$ = initial temperature = $25^oC=273+25=298 K$

$T_2$ = final temperature = $4^oC=273+4=277 K$

Now put all the given values in this formula, we get:l

$\log (\frac{k}{40k})=\frac{Ea}{2.303\times 8.314 J/mol K}[\frac{1}{298K}-\frac{1}{277 K}]$

$E_a=120,575.61J=120.575 kJ$

120.575 kJ is the activation energy for the souring process.

7 0

3 years ago

Minerals are very useful to us. Which of the following is a false statement? Question options: Pyrite is an ore of gold and is u

Andrew [12]

Answer:

Option C= Cobalt is not used in medicine

This statement is incorrect.

Explanation:

Pyrite is an ore of gold and is used in jewelry making (correct statement)

Pyrite:

1. pyrite is yellow brass mineral.

2. its chemical composition is FeS2.

3. it is also called ore of gold

4. it is used in jewelry.

Talc:

Talc is used in paper making, plastics, and paint (correct statement)

1. it is phyllosilicate mineral in the form of sheets.

2. its chemical formula is Mg3Si4O10 (OH)2.

3. it is very important constituent of roofing material.

4. it is used in many industries like paper making, paints, electrical cables, food etc.

Quartz:

Quartz is used to make glass (correct statement)

1. its chemical formula is SiO2.

2. its large amount is used in manufacturing of ceramic and glass.

3. The second most abundant mineral found in the earth crust is also quartz.

Cobalt:

Cobalt is not used in medicine (incorrect statement)

1. Cobalt is widely used in medical field.

2. it is used in the detection of metastasis and tumor.

3. it is used in the replacement of knee and hip as a prosthetic alloys.

Minerals are very important in our daily life. They are widely used in construction material for example in the construction of buildings and roads and also in medical field.

Examples:

1. Copper is used in the electronic and electrical field.

2. Zinc is used in rust resistant metals, skin care creams. rubber paints etc.

8 0

3 years ago

List the number of each type of atom on the right side of the equation hbr(aq)+2naoh(aq)→2nabr(s)+h2o(l)

ser-zykov [4K]

On the basis of the given unbalanced equation, that is:

HBr (aq) + 2NaOH (aq) → 2NaBr (s) + H2O (l)

On the right side of the equation, there are 2 atoms of sodium (Na), 2 atoms of bromine (Br), 2 atoms of hydrogen (H), and 1 atom of oxygen (O₂).

After balancing the equation correctly we get:

HBr (aq) + NaOH (aq) → NaBr (s) + H2O (l)

On the right side, one atom of Na, 1 atom of Br, 1 atom of H and one atom of O₂.

5 0

2 years ago

Read 2 more answers

What percentage of carpet is calcium carbonates?

e-lub [12.9K]

Answer:

the percentage of carpet is calcium carbonates is 12.456734190

5 0

3 years ago

7.7. A painter leans his back against a painted wall while looking into a 1m long mirror at the opposite end of a rectangular ro

Karolina [17]

Answer:

Correct answer is b) 2m

Explanation:

8 0

3 years ago

7. The youngest part of the ocean floor is found ____.