(1) Br2(ℓ) (3) KBr(s)
(2) K(s) (4) KBr(aq)
Answer:
KBr (aq) is a mixture.
Explanation:
Mixture is defined as the combination of two non reacting species. Let's discuss each option one by one.
a) Br₂(l):
This Bromine is not a mixture because the bracket specifying the state of Br₂ is liquid. Hence, as bromine is a liquid at room temperature, so this compound is purely Br₂.
b) KBr (s):
KBr is also present in pure form because in bracket solid is written.
c) K (s):
Potassium is also present in pure form as the bracket is specifying solid, as KBr is solid at room temperature.
d) KBr (aq):
This is a mixture of KBr and water. Because KBr being an electrolyte when dissolved in water it is hydrated as follow,
KBr (s) -----water------> K⁺ (aq) + Br⁻ (aq)
is a mixture.
Further explanation:
Mixture:
It is formed by the physical combination of two or more different substances. Mixtures do not have any fixed formula and their composition is also variable. There is retention in the properties of constituents even after the formation of mixtures.
(1)
Bromine is present in liquid in its pure state. The “l” written in the parenthesis after denotes its physical state which is the same as that of its pure form. So it is not a mixture.
(2) K (s)
Potassium is present in solid in its pure form. The “s” written in the parenthesis after K describes its physical state which is the same as that of its pure form. So it is not a mixture.
(3) KBr (s)
It is an ionic salt which is solid in nature. The “s” written in the parenthesis after KBr denotes its physical state which is the same as that of its pure form. So it is not a mixture.
(4) KBr (aq)
The “aq” written in the parenthesis after KBr indicates that it is present in the aqueous phase. This means it is formed by the combination of KBr and water so it is a mixture.
Learn more:
Answer details:
Grade: High School
Chapter: Elements, compounds, and mixtures
Subject: Chemistry
Keywords: mixture, physical combination, substances, fixed formula, variable, composition, retention, properties, Br2, K, KBr.
B 1.5 X 1-^-5 ppm
C 0.061 ppm
D 15 ppm
Answer: The correct option is C.
Explanation: ppm is used to measure the concentration of solute in a given volume of solution. ppm is basically parts per million.
Mathematically,
We are given:
Mass of methanol = (Conversion Factor : 1g = 1000mg)
Volume of solution = 250 mL = 0.250L (Conversion Factor : 1L = 1000mL)
Putting values in above equation, we get:
Concentration of methanol = 0.062ppm
Hence, the correct option is C.