All categories

3 years ago

How many C atoms are there in 5.25 grams of a compound containing 92.26% C and 7.74% H?

1 answer:

7 0

Take 5.25 grams and give it proportionally to the carbon
0.9226 * 5.25 grams = 4.84 grams Carbon
Find the number of moles
(4.84 grams carbon)/(12.01 grams/mol) = 0.403 moles Carbon
The number of atoms in a mole of a substance is called Avogadro's number.
There are 6.022 * 10^23 atoms in one mole of anything
(0.403 moles Carbon) * (6.022 * 10^23 atoms/mole) = 2.43 * 10^23 atoms of Carbon

You might be interested in

What would it take for Americans today to favor a greater reliance on nuclear power as a source of electricity

Ierofanga [76]

Answer:

yes

Explanation:

mmmm

7 0

3 years ago

One of the radioactive isotopes used in medical treatment or analysis is chromium-51. The half-life of chromium-51 is 28 days. H

Goryan [66]

Answer : The time required for decay is, 84 days.

Explanation :

Half-life of chromium-51 = 28 days

First we have to calculate the rate constant, we use the formula :

$k=\frac{0.693}{t_{1/2}}$

$k=\frac{0.693}{28\text{ days}}$

$k=0.0248\text{ days}^{-1}$

Now we have to calculate the time required for decay.

Expression for rate law for first order kinetics is given by:

$t=\frac{2.303}{k}\log\frac{a}{a-x}$

where,

k = rate constant

t = time taken by sample = ?

a = let initial activity of the sample = 100

a - x = amount left after decay process = 12.5

Now put all the given values in above equation, we get

$t=\frac{2.303}{0.0248}\log\frac{100}{12.5}$

$t=83.9\text{ days}\approx 84\text{ days}$

Therefore, the time required for decay is, 84 days.

7 0

3 years ago

15. Which characteristic of a substance will NOT

Andrej [43]

Boiling point. Hope this helps

5 0

2 years ago

How does mechanical energy depend on other forms of energy??

Ksenya-84 [330]

Answer:

Other forms of energy can convert to mechanical energy

Explanation:

For example the electric or magnetic energy in a motor can convert to mechanical energy, or another example is when you put two magnets together they will clip together due to the magnetic energy that they have.

5 0

3 years ago

Nick hypothesizes that wax has a higher melting point than chocolate how can he test his hypothesis

LUCKY_DIMON [66]

Melt chocolate and measure the temperature and then melt wax and measure the temperature and compare his results.

5 0

3 years ago