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
Morgarella [4.7K]
4 years ago
9

The half life of a certain substance is 28 years. how long will it take for a sample of this substance to decay to 78% of its or

ginal amount.
Chemistry
1 answer:
saw5 [17]4 years ago
5 0
The life= 28*2 =56
100% -78%=22%
56*22/100 = 12,32 years to decay 22% of it s original amount / and there remains 78 % of the original amount .
You might be interested in
For the reaction 2 NO(g) + 2 H2(g) => N2(g) + 2 H2O(g) the following data were collected. What is the rate law for this react
harkovskaia [24]

<u>Answer:</u> The rate law expression for the given reaction is written below.

<u>Explanation:</u>

Rate law is defined as the expression which expresses the rate of the reaction in terms of molar concentration of the reactants with each term raised to the power their stoichiometric coefficient of that reactant in the balanced chemical equation.

For the given chemical equation:

2NO(g)+2H_2(g)\rightarrow N_2(g)+2H_2O(g)

Rate law expression for the reaction:

\text{Rate}=k[NO]^2[H_2]^2

Hence, the rate law expression for the given reaction is written above.

5 0
3 years ago
135 grams of sodium has ______ moles.<br><br> (Enter just the number for this one.)
just olya [345]

Answer : 135 grams of sodium has 5.869 moles.

Solution : Given,

Mass of sodium = 135 grams

Molar mass of sodium = 23 g/mole

Formula used :

\text{Moles of sodium}=\frac{\text{Mass of sodium}}{\text{Molar mass of sodium}}

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

\text{Moles of sodium}=\frac{135g}{23g/mole}=5.869moles

Therefore, the moles of sodium present in 135 grams of sodium is, 5.869 moles.


6 0
3 years ago
What is the osmotic pressure, in torr, of a 3.00% solution of NaCl in water when the temperature of the solution is 45 ºC? Enter
Anit [1.1K]

213034 torr is the osmotic pressure.

Explanation:

osmotic pressure is calculated by the formula:

osmotic pressure= iCrT

where i= no. of solute

c= concentration in mol/litre

R= Universal Gas constant

T = temp

It is given that solution is 3% which is 3gms in 100 ml.

let us calculate the concentration in moles/litre

3gm/100ml*1000ml/1L*1mol NaCl/55.84g NaCl

= 5.372 gm/litre

Putting the values in the formula,                   Temp in Kelvin 318.5K

osmotic pressure= 2*5.372*0.083 * 318.5                 Gas constant  0.083

                              = 284.023 bar or 213018 torr.                 c=  5.372 moles/L                                                                              

                                                                                    i=2 for NaCl

4 0
3 years ago
Another name for chemical change
elena-14-01-66 [18.8K]
Another name for chemical change would be chemical reaction.
8 0
4 years ago
Read 2 more answers
Which statement best describes temperature? A.
USPshnik [31]
?? post the statements
4 0
4 years ago
Read 2 more answers
Other questions:
  • Given the information shown in process "B", calculate the molar enthalphy of fusion for ice
    9·1 answer
  • Na (atomic no. 11) reacts with Cl (atomic no. 17) to become stable. In the reaction, Na will ____________, while Cl will _______
    7·1 answer
  • How is energy Associated with food stored
    9·2 answers
  • Estimate the volume of the football. Compare the football to the table tennis balls by dragging the football over the
    12·2 answers
  • What is the ΔG given the following? ΔH = 20 kJ/mol T = 15°C ΔS = .101 kJ/molK
    14·1 answer
  • ______ will have a higher entropy than 50.0 g CO2 (g) at 56 oC.
    6·1 answer
  • Coca cola is similar to tomato juice because
    11·2 answers
  • What is the condition of water in the hydrosphere right now?
    14·1 answer
  • HELP ASAP
    8·1 answer
  • What is the volume of a gas if 0.182 moles of the gas is at 1.99 atm and 83.4oC?
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!