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
Ulleksa [173]
3 years ago
11

the half-life of a certain radioisotope is 12 days. how much (mass) of a 60 mg sample will remain after 36 days

Chemistry
1 answer:
bixtya [17]3 years ago
6 0

Answer:3.5

Explanation:

You might be interested in
Question 19 Unsaved
aliina [53]

It described a nucleus surrounded by a large volume of space.

7 0
3 years ago
Determine the [OH−] , Ph, and POH of a solution with a [H+] of 0. 00017 m at 25 °C.
tino4ka555 [31]

Main Answer:

Given

pH = -log[H+]

= -log[0.00017]

= 3.769

We know that

pW = pH + pOH

and pW =14

pOH = 14-pH

=14-3.769

=10.231

According to the definition

pOH = -log[OH-]

10.231 = log[OH-]-1

[OH-]= 5.87 x 10-11

Explanation:

What is pH?

pH is defined as the concentration of H+ ion in the solution. If the pH value is less than 7, then the solution will be acidic. If the pH value is greater than 7, then the solution will be basic.

To know more about pH, please visit:

brainly.com/question/8758541

#SPJ4

4 0
2 years ago
A 1.00 g sample of octane (C8H18) is burned in a bomb calorimeter with a heat capacity of 837J∘C that holds 1200. g of water at
lubasha [3.4K]

Answer:

The heat of combustion for 1.00 mol of octane is  -5485.7 kJ/mol

Explanation:

<u>Step 1:</u> Data given

Mass of octane = 1.00 grams

Heat capacity of calorimeter = 837 J/°C

Mass of water = 1200 grams

Temperature of water = 25.0°C

Final temperature : 33.2 °C

<u> Step 2:</u> Calculate heat absorbed by the calorimeter

q = c*ΔT

⇒ with c = the heat capacity of the calorimeter = 837 J/°C

⇒ with ΔT = The change of temperature = T2 - T1 = 33.2 - 25.0 : 8.2 °C

q = 837 * 8.2 = 6863.4 J

<u>Step 3:</u> Calculate heat absorbed by the water

q = m*c*ΔT

⇒ m = the mass of the water = 1200 grams

⇒ c = the specific heat of water = 4.184 J/g°C

⇒ ΔT = The change in temperature = T2 - T1 = 33.2 - 25  = 8.2 °C

q = 1200 * 4.184 * 8.2 =  41170.56 J

<u>Step 4</u>: Calculate the total heat

qcalorimeter + qwater = 6863.4 + 41170. 56 = 48033.96 J  = 48 kJ

Since this is an exothermic reaction, there is heat released. q is positive but ΔH is negative.

<u>Step 5</u>: Calculate moles of octane

Moles octane = 1.00 gram / 114.23 g/mol

Moles octane = 0.00875 moles

<u>Step 6:</u> Calculate heat combustion for 1.00 mol of octane

ΔH = -48 kJ / 0.00875 moles

ΔH = -5485.7 kJ/mol

The heat of combustion for 1.00 mol of octane is  -5485.7 kJ/mol

8 0
3 years ago
At constant temperature a bicycle tire pump contains 252mL of air at 995kPa pressure. The plunger of the pump is pushed down unt
Novay_Z [31]

Answer:

The new pressure of the pump is 26.05 atm or 2639.4 kPa

Explanation:

Step 1: Data given

Volume of the bicycle tire pump = 252 mL = 0.252 L

Pressure of air = 995 kPa = 9.81989 atm

The volume of the pump is reduced to 95.0 mL = 0.095 L

Step 2: Calculate the new pressure

V1*P1 = V2*P2

⇒with V1 = the initial volume of the bicycle tire pump = 0.252 L

⇒with P1 = the initial pressure of the pump = 9.81989 atm = 995 kPa

⇒with V2 = the reduced volume of the pump = 0.095 L

⇒with P2 = the new pressure = TO BE DETERMINED

0.252 L * 9.81989 atm = 0.095 L * P2

P2 = 26.05 atm

The new pressure is 26.05 atm

OR

0.252 L * 995 = 0.095 L * P2

P2 = 2639.4 kPa

The new pressure of the pump is 26.05 atm or 2639.4 kPa

4 0
3 years ago
Read 2 more answers
101.325 kPa = 760 mmHg. So, 25.0 kPa is
gogolik [260]
101.325 kPa = 760 mmHg.
So, 25.0 kPa is 187.515 mmHg
5 0
3 years ago
Other questions:
  • The average density of whole milk is 1.034 g cm ^3. What is it’s density in lb gal ^-1?
    10·2 answers
  • the overall take away of an experiment’s results is the______. A. hypothesis B. introduction C. conclusion
    15·2 answers
  • According to john dalton, elements consist of tiny particles called __________. Atoms of each element are __________ to each oth
    6·1 answer
  • What is the purpose of adding antifreeze to the water in the radiator of a car?
    12·2 answers
  • When using the benedict's assay, which color would indicate the most reducing sugar present?
    12·1 answer
  • What is the pH of an HNO3 solution with a molarity of 0.023? ( hint: pH = -log[H+] )
    15·1 answer
  • Ammonium phosphate NH43PO4 is an important ingredient in many solid fertilizers. It can be made by reacting aqueous phosphoric a
    11·1 answer
  • Calculate the number of oxygen atoms in a 80.0 g sample of scheelite (CaWo).
    6·1 answer
  • Un hidrocarburo tiene la siguiente composición: 92,3% en carbono y 7,7% en hidrógeno. La masa molecular de este compuesto se enc
    9·1 answer
  • 3. The number of electrons and neutrons in an atom are 13 and 14, respectively. Find out the mass number, atomic number, valency
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!