1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Tresset [83]
3 years ago
12

The half-life of sodium-24 is 15 days. A laboratory technician measures out a 72 g sample. Approximately how many grams of sodiu

m-24 would remain after 45 days?
Chemistry
1 answer:
Vanyuwa [196]3 years ago
6 0

Answer:

after 45 days 9 g left

Explanation:

Given data:

Half life Na-24 = 15 days

Mass of sample = 72 g

Mass remain after 45 days = ?

Solution:

Number of half lives passed:

Number of half lives = time elapsed / half life

Number of half lives = 45 days / 15 days

Number of half lives = 3

At time zero total amount = 72 g

After first half life = 72 g/ 2= 36 g

At 2nd half life = 36 g/2 = 18 g

At 3rd half life = 18 g/2 = 9 g

Thus after 45 days 9 g left.

You might be interested in
In an experiment, marble chips reacted with dilute hydrochloric acid and carbon dioxide gas was given
laiz [17]

Answer:

no

Explanation:

Small marble chips reacts faster

7 0
3 years ago
How much heat, in joules, must be added to a 75.0-g iron block with a specific heat of 0.449 J/g °C to increase its temperature
svp [43]

Answer:

50,849.25 Joules

Explanation:

The amount of heat, Q, required to raise the temperature of a body with mass, m, and specific heat capacity, c is given by:

Q = mcΔT, where ΔT represents the change in temperature.

In the case of the iron block:

m = 75 g

c = 0.449 J/g °C

ΔT = 1535 - 25 = 1510 °C

Therefore,

Q = 75 g x 0.449 J/g °C x 1510 °C

     = 50,849.25 Joules

<em>Hence, </em><em>50,849.25 Joules </em><em> of heat must be added to  a 75.0-g iron block with a specific heat of 0.449 J/g °C to increase its temperature from 25 °C to its melting temperature of 1535 °C</em>

5 0
3 years ago
Hydrazine, N2H4, may react with oxygen to form nitrogen gas and water.
Sindrei [870]

Answer:

The percent yield of the reaction is 35 %

Explanation:

In the reaction, 1 mol of hydrazine reacts with 1 mol O₂ to produce 1 mol of nitrogen and 2 moles of water.

Let's verify the moles that were used in the reaction.

2.05 g . 1mol/ 32 g = 0.0640 mol

In the 100% yield, 1 mol of hydrazine produce 1 mol of N₂ so If I used 0.0640 moles of reactant, I made 0.0640 moles of products.

Let's use the Ideal Gases Law equation to find out the real moles of nitrogen, I made (real yield).

1atm . 0.550L = n . 0.082 . 295K

(1atm . 0.550L) / 0.082 . 295K = n → 0.0225 moles

Percent yield of reaction = (Real yield / Theoretical yield) . 100

(0.0225 / 0.0640) . 100 = 35%

3 0
3 years ago
Read 2 more answers
Which term is used to describe the variety of inheritable traits in a species? (4 points)
Nookie1986 [14]

Answer:

B Genetic diversity

Explanation:

6 0
3 years ago
Read 2 more answers
Which option defines kinetic energy?(1 point)
MAVERICK [17]

The option which accurately defines kinetic energy from the choices above is:

the energy an object has because of its motion

The correct answer choice is option c

In order words, kinetic energy is that type of energy which a body or an object posess due to its relative motion.

<h3>What is energy?</h3>

Energy can simply be defined as the capacity of doing work.

Energy is a derived quantity; meaning that it is obtained from the combination of fundamental quantities.

The unit of energy joules.

Other examples of derived quantities just like energy too are:

  • Volume
  • Speed
  • Acceleration
  • Density.
  • Upthrust
  • Momentum
  • Momentum
  • Power
  • Pressure
  • Force

Below are some few forms of energy; these are:

  • Kinetic energy
  • Potential energy
  • Mechanical energy
  • Solar energy
  • Light energy
  • Chemical energy

So therefore, the option which accurately defines kinetic energy from the choices above is:

the energy an object has because of its motion

Learn more about energy:

brainly.com/question/25959744

#SPJ1

3 0
1 year ago
Read 2 more answers
Other questions:
  • Given that the molar mass of carbon is 12 g/mol and the molar mass of oxygen is 16 g/mol, calculate the molar mass of carbon dio
    12·1 answer
  • Can you help me on my science
    9·1 answer
  • The movement of organisms into a range is called
    13·1 answer
  • The properties of two elements are listed below. Element Atomic radius (pm) Ionic radius (pm) First ionization energy (kJ/mol) E
    7·1 answer
  • Select the correct coefficients to balance the reaction given below.<br> __Al + ___O₂ → ____ Al₂ O₃
    11·1 answer
  • How do you make fried chicken im white and don't know how to season
    5·1 answer
  • Water boils at 212 degrees
    15·1 answer
  • 54:63 ratio simplest form?
    11·1 answer
  • If there are 94 different kinds of naturally occurring atoms how many different naturally occurring elements are there?
    14·1 answer
  • During what change is heat absorbed?
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!