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
astraxan [27]
3 years ago
13

When does a change in energy occur?

Chemistry
1 answer:
MrRa [10]3 years ago
6 0
3. in every chemical or physical change
You might be interested in
If a particular ore contains 55.4 % calcium phosphate, what minimum mass of the ore must be processed to obtain 1.00 kg of phosp
gizmo_the_mogwai [7]
 The ore contains 55.4% calcium phosphate (related to the mineral apatite) so the amount of Ca3(PO4)2 is 55.4%x=1000g so x=1000/0.554= 1.805kg. Now for the % of P in this amount of calcium phosphate, use all the masses of the elements in Ca3PO4= Ca=40.078 x 3= 120.23 and (PO4)2= (30.974+64)2=189.95  (NB oxygen is 16 mass x 4 =64) so the total mass is 310.2 and we have 61.95 of P (Pmass x 2) so 61.95/3102.= 0.19 or 19% P. So of the 1.805 x 0.19= 0.34kg of phosphorus.
8 0
4 years ago
How would you calculate the molar mass of 2AgCl?
Rashid [163]
2 × (atomic mass of Ag) + (atomic mass of Cl (
3 0
3 years ago
How is it possible for scientists to do studies about things that happened?
Levart [38]

Because they can look at the fossils that they left behind and see what kind of animal it was and what happened to it if another animal is inside of the fossil or if the bones are misplaced

6 0
3 years ago
Which of these following have a positive charges
Over [174]
Talking about ions, a cation has a positive charge. That means a positive charge is gained by an atom that gives out electrons. 
7 0
3 years ago
A compound that is usually used as a fertilizer can also be used as a powerful explosive. the compound has the composition 35.00
maxonik [38]

Answer:

             Empirical Formula  =  NH₄NO₃ (Ammonium Nitrate)

Solution:

Step 1: Calculate Moles of each Element;

                      Moles of N  =  %N ÷ At.Mass of N

                      Moles of N  = 35.0 ÷ 14

                      Moles of N  =  2.5 mol


                      Moles of O  =  %O ÷ At.Mass of O

                      Moles of O  = 59.96 ÷ 16

                      Moles of O  =  3.7475 mol


                      Moles of H  =  [100% - (%N + %O)] ÷ At.Mass of H

                      Moles of H  = [100% - (35.0 + 59.96)] ÷ 1.008

                      Moles of H  = [100% - 94.96] ÷ 1.008

                      Moles of H  = 5.04 ÷ 1.008

                      Moles of H  =  5 mol

Step 2: Find out mole ratio and simplify it;

                N                                        H                                     O

               2.5                                       5                                3.7475

            2.5/2.5                                5/2.5                          3.7475/2.5

                 1                                         2                                     1.5

Multiply Mole Ratio by 2,

                 2                                         4                                     3

Result:

         Empirical Formula  =  N₂H₄O₃

Or,

         Empirical Formula  =  NH₄NO₃

This empirical formula is also a Molecular Formula for Ammonium Nitrate a well known Fertilizer and often misused in the formation of Explosives.

4 0
3 years ago
Other questions:
  • 8. Balance the following nuclear equations:<br> ^65/30Ca -&gt; ^65/29Sc +_______
    15·1 answer
  • Which of these best matches a planet in the solar system with its characteristic?
    14·2 answers
  • QUE NOMBRE RECIBE LA MASA GASEOSA QUE ENVUELVE LA TIERRA
    9·1 answer
  • When the final velocity is less than the initial velocity, this is speed time acceleration deceleration
    13·2 answers
  • Where would the temperature of the ocean's surface water be the lowest?
    12·2 answers
  • Ava’s best friend has an indoor cat. Ava notices that she sneezes every time that she visits her friend. Ava suspects that she i
    9·1 answer
  • A change in which property of light will have no effect on whether or not the photoelectric effect occurs??? Frequently energy i
    5·2 answers
  • 3 electron layers in the electron shell and 1 electron in the last electron layer​
    5·1 answer
  • What occurs when a reaction reaches equilibrium?
    12·2 answers
  • What does 1 carbon and 1 sulfur make
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!