<h3><u>Answer</u>;</h3>
A. When a reaction is at chemical equilibrium, a change in the system will cause the system to shift in the direction that will balance the change and help the reaction regain chemical equilibrium.
<h3><u>Explanation</u>;</h3>
- Le Chatelier's principle states that when a change or a "stress" is placed on a system that is at equilibrium, the system will shift in such a way to relieve that change or stress.
- The stresses include; changing the concentration of reactants or products, altering the temperature in the system and changing the pressure of the system.
- Therefore; <u><em>when a chemical reaction is at equilibrium and experiences a change in pressure, temperature, or concentration of products or reactants, the equilibrium shifts in the opposite direction to offset the change. </em></u>
The blue color of copper (ii) sulfate will change to green, yellow, orange ,red and then a dark red or brown.
Glucose is a reducing sugar; reducing sugars are sugar that forms an aldehyde or ketone in the presence of an alkaline solution. Reducing sugars reduce the blue copper sulfate from the Benedict's solution to a red brown copper sulfide; which is seen as the precipitate and is responsible for the color change.
Answer:
B
Explanation:
Balanced equations have the same number of elements on both sides. If the number of elements are equal to each other for every element in the equation on both sides, then the equation is balanced.
Important concept : The big number before an element or compound represents how many molecules of that compound or element there are in a reaction. To find the number of atoms of each element you multiply the coefficient by the subscript ( small number ) which represents the number of atoms of that element in each molecule. Ex. 3H2O. There is a coefficient of 3 meaning that there are 3 molecules of H2O. There is a subscript after H meaning there are 2 atoms of hydrogen in each molecule. To find the total number of atoms we multiply the subscript of hydrogen by the coefficient of the whole molecule. 3 * 2 = 6 , so there are a total of 6 atoms of hydrogen in 3H2O
A) Cu + 2AgNO3 ==> CuNO3 + 2Ag
1 Cu 1
2 Ag 2
2 N 1
3 O 3
The amount of nitrogen atoms is different on both sides of the equation therefore this is not a balanced equation
B) CCl4 + O2 ==> CO2 + 2Cl2
1 C 1
4 Cl 4
2 O 2
The number of atoms of each element is the same on both sides of the equation therefore this is the balanced equation, however lets check the other answer choices just in case.
C) 2K + H2SO4 ==> K2SO4 + 2H2
2 K 2
1 H 4
1 S 1
4 O 4
The number of Hydrogen atoms are different on each side of the equation therefore this is not a balanced equation.
D) 2Al2O3 ==> 2Al + 3O2
4 Al 2
6 O 6
There are a different amount of aluminum atoms on both sides of the equation therefore this is not a balanced equation.
