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.
Answer:
No
Explanation:
The pH scale is a scale graduated from 0-14 which shows the degree of acidity of alkalinity of a substance. The pH scale is graduated in such a way that 0-6.9 indicates acidity, 7.0 indicate a neutral substance, while a pH of 8-14 indicates alkalinity respectively.
There are three main definitions of acids/bases
- Arrhenius definition
-Brownstead-Lowry definition
-Lewis definition
Arrhenius explains acids as any substance that produces hydrogen ions as its only positive ion in solution while a base produces hydroxide ions as its only negative ion in solution. The pH scale is based on corresponding values of pH derived from aqueous solutions of these substances.
However, not all acids/bases produces hydrogen or hydroxide ions in solution. Brownstead-Lowry definition of acids and Lewis definition of acids could be extended to nonaqueous media where the pH can not be measured as there are no hydrogen or hydroxide ions present in the solution.
This implies that pH measurement may not apply to acids/bases in the all the categories of acids/bases hence it can not be utilized for all acids and bases.
Arrhenius - sodium carbonate
Brownstead-Lowry - concentrated HF
Lewis acid - AlCl3
Answer:
The correct answer is because the molecular structure.
Explanation:
The difficulty of ammonia and methane to be represented on paper is due to the molecular structure. These compounds have a three-dimensional projection with defined angles. Ammonia presents angles of 109.5º between the atom of Nitrogen and those of Oxygen. The ammonia presents 107.8º between the oxygen atoms.
In the methane molecule, there is 109.5º between the hydrogen molecules and the carbon atom. This results in the need for a 3D representation of the molecule.
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