It's the law! Matter cannot be created or destroyed in chemical reactions. This is the law of conservation of mass. In every chemical reaction, the same mass of matter must end up in the products as started in the reactants.
Answer : The correct answer is A. Nuclear reactors using Pu-239
B. burning coal
The sources which are not renewable are known as "non- renewable sources of energy .
Non - renewable sources are those which get expired after rapid use and can never be reproduced . These sources replenishes in very long time . Examples : Coal , petrol or fuels etc .
1) Nuclear reactors using Pu-239 : Nuclear reactors uses radioactive elements like uranium , plutonium etc , which are present in limit . after frequent use of these elements , they will vanish off , Hence we can say nuclear reactors are Non renewable source of energy .
2) Burning coal : Coal is used as one of the major source of fuel . On rapid utilization of coal they will finished from earth . It takes thousand of year for formation of coal . Hence , it is a Non -renewable source .
3) Photo-voltaic cell: These are cells which used solar energy . Solar energy is obtained from sun . Hence solar energy is renewable source of energy so is the photo voltaic cell .
4) Geothermal energy : Geothermal energy is source of energy that is extracted from earth's thermal energy . Since thermal energy of earth is present in very large amount and can be reproduced , hence it renewable source of energy .
5)Wind energy : Wind energy is source of energy that is obtained from wind. And wind is renewable source so the wine energy too .
Consequently , we can say only two of them " Nuclear reactors and burning of coal " are Non renewable force of energy .
The molecular formula is D. C_8H_20O_4Si.
<em>Step 1</em>.Calculate the <em>empirical formula
</em>
a) Calculate the moles of each element
Moles of C= 196.01 g C × (1 mol C/12.01 g C) = 16.325 mol C
Moles of H = 41.14 g H × (1 mol H/1.008 g H) = 40.813 mol H
Moles of O = 130.56 g O × (1 mol O/16.00 g O) = 8.1650 mol O
Moles of Si = 57.29 g Si × (1 mol Si/28.085 g Si) = 2.0399 mol Si
b) Calculate the molar ratio of each element
Divide each number by the smallest number of moles and round off to an integer
C:H:O:Si = 8.0027:20.008:4.0027:1 ≈ 8:20:4:1
c) Write the empirical formula
EF = C_8H_20O_4Si
<em>Step </em>2. Calculate the <em>molecular formula</em>
EF Mass = 208.33 u
MF mass = 208.329 u
MF = (EF)_n
n = MF Mass/EF Mass = 208.329 u/208.33 u = 1.0000 ≈ 1
MF = C_8H_20O_4Si
Answer:
: the answer is C
Explanation:
:State the law of conservation of energy.
Define and endothermic process.
Define an exothermic process.
Make conversions involving heat units.
