Answer:-
Solution:- As is clear from the given Ka value, Cinnamic acid is a weak acid. let's calculate the moles of acid and KOH added to it from their given molarities and mL.
For KOH, 
= 0.002 mol
For Cinnamic acid, 
= 0.003 mol
Acid and base react as:
The reaction takes place in 1:1 mol ratio. Since the moles of acid are in excess, the acid is still remaining when all the kOH is used.
0.002 moles of KOH react with 0.002 moles of Cinnamic acid to form 0.002 moles of potassium cinnamate. Excess moles of Cinnamic acid = 0.003 - 0.002 = 0.001
As the solution have weak acid and it's salt(or we could say conjugate base), it is a buffer solution and the pH of the buffer solution could easily be calculated using Handerson equation:
pKa could be caluted from given Ka value using the formula:
pKa = - log Ka
pKa = 4.44
let's plug in the values in Handerson equation and calculate the pH:
pH = 4.44+0.30
pH = 4.74
So, the first choice is correct, pH is 4.74.
Answer:
A. 2
Explanation:
You need to balance the other side so the reactants and products are equal.
Answer:
Gasoline
Explanation:
Pure Substance: are those having same type of atoms or molecules.
Compound: one or more atoms of the element combine to form a compound.
Mixture: is combination of one or more substances mix together.
Homogeneous Mixture: are those which are not distinguish by naked eye but can be separated into its components by physical means
Heterogeneous mixture: are those which can be distinguishing by naked eye and can be separated into its components by physical means.
So keeping in mind the above definitions
Table salt:
The chemical formula of table salt is NaCl and it a pure compound not mixture.
Gasoline:
Gasoline is mixture of hydrocarbon, It contains small hydrocarbons ranging from 4 Carbon to 12 Carbon per molecule. it is a homogeneous mixture.
Aluminum:
Aluminum is a pure substance that is made up of same kind of atoms. so it is an element and not mixture. Its symbol is Al
Carbon dioxide:
Carbon dioxide is a pure compound and its chemical formula is CO₂ and not a mixture.
So, the write option is Gasoline.
Answer:
H20
water (the chemical symbol, as used in non-specific contacts. 8 equals hydrogen equals oxygen and two elements in hydrogen therefore is known as H2O .
H202
hydrogen peroxide equals hydrogen peroxide is the chemical compound with formula h202. And it's your form, it is very pale blue liquid, slightly more vicious than water. It is used as an oxidizer, bleaching agent, and antiseptic .
Co=
carbon monoxide, carbon monoxide is colorless, odorless, and tasteless flammable gas that is slightly less dense than air. Formula equals Co
Answer:
Compound formula : HCl
Element H
# atoms:1
Elements Cl
#atoms : 1
gram formula weight (g) = 36.46
