The factors that affect the rate of a reaction are:
- <em>nature of the reactant</em> - when reactants with different chemical composition are exposed to same conditions they would react differently. For instance, when an acid or base is added on litmus paper, blue litmus paper turns red in presence of acid while red litmus paper turns blue when base is added.
- <em>surface area</em>- a compound with small pieces spread over a large area will react faster than a big lump of a compound occupying a small area.
- <em>temperature of reaction</em>- reactants would react faster at high temperatures. this is because they have higher kinetic energy to collide with each other. Hence a plate of food on the table spoils faster than a plate of food in the fridge.
- <em>concentration</em>- an increase in concentration leads to more molecules available to collide and form products. An example, when you add more of indicator in a solution, the color becomes more clear since more particles react to give more color.
- <em>presence of a catalyst</em>- a catalyst lowers the activation energy, which means less energy is required to shift reaction in forward direction. In the presence of iron (Fe) a catalyst, nitrogen N₂ and hydrogen H₂ react to produce NH₃
Oxidation number is defined as the total number of electrons that are gained or lost by the atom to form a chemical bond.
the oxidation number of the compound H₂S is 0.
the sum of the oxidation numbers of the individual elements should add up to the oxidation number of the compound.
(oxidation number of H x 2 H ions) + oxidation number of S = 0
since we know the oxidation number of H, lets name the oxidation number of S = x
(+1 * 2 )+ (x) = 0
2 + x = 0
x = -2
oxidation number of S is -2
Answer:
crystalline and amorphous.
Explanation:
Crystalline solids are the most common type of solid, they are characterized by a regular crystalline organization of atoms that confer a long-range order, Amorphous, or non-crystalline, solids lack the long-range order
That is choice A.
The products are different from the reactants.
This may be easy to see - for example when one of the products is precipitated, like when you add BaCL2 to Na2SO4. The BaSO4 formed is insoluble in water and appears as a white precipitate.
Answer:
mass molar of gas (Mw):
Mw = 107 g/mol
Explanation:
∴ m gas = 3.82 g
∴ V gas = 0.854 L
∴ T = 302 K
∴ P = 1.04 atm
ideal gas:
∴ n = m / Mw
⇒ PV = RTm/Mw
⇒ Mw = RTm / PV
⇒ Mw = ((0.082 atm.L/K.mol)*(302 K)*(3.82 g)) / ((1.04 atm)*(0.854 L)
⇒ Mw = 106.51 g/mol ≅ 107 g/mol
