Answer:
A solution that is 0.10 M HCN and 0.10 M LiCN
Explanation:
- A good buffer system contains a weak acid and its salt or a weak base and its salt.
- In this case; A solution that is 0.10 M HCN and 0.10 M LiCN, would make a good buffer system.
- HCN is a weak acid, while LiCN is a salt of the weak acid, that is, CN- conjugate of the acid.
Answer: a
Explanation: because an Arrhenius acid is a compound that increases the H + ion concentration in aqueous solution. An Arrhenius base is a compound that increases the OH − ion concentration in aqueous solution.
<span>As we know that
1 cu cm H2O = 1 mL H2O = 1g H2O
now
Heat of fusion of water = 79.8 cal/g
and
Heat of vaporization of water = 540 cal/g
Atomic weight of water : H=1 O=16 H2O=18
now by calculating and putting values
65.5gH2O x 79.8cal/gH2O x 1gH2O/540cal = 9.68g H2O (steam)
9.68gH2O x 1molH2O/18gH2O x 22.4LH2O/1molH2O = 12.0 L H2O
hope it helps</span>
Answer: a. two substances present; two phases present : Heterogeneous mixture
b. two substances present; one phase present
: Homogeneous mixture
c. one substance present; one phase present
: pure substance.
d. one substance present; two phases present: Heterogeneous mixture
Explanation:
A pure substance is a substance which contains definite composition of only one type of component. Hence, it cannot be separated by physical means.
Mixture is a substance which contains two or more than two types of components and they can be separated by physical means as well.
Homogeneous mixtures: It is a mixture that has uniform composition throughout the solution and the particle size or shapes are not different. There is no physical boundary between the dispersed phase and dispersion medium.
Heterogeneous mixtures: It is a mixture that has non-uniform composition throughout the solution and the particle size or shapes are also different. There is a physical boundary between the dispersed phase and dispersion medium.
Answer:
The two observations we made from viewing the solar system model are as follows as:
1). When we look at the sky we observe that the motions of all the planets and the stars are perfect circular movements with a good and high speed, but not in velocity because in velocity direction doesn't charges.
2). The sun is at the centre of our solar system and all the planets are equidistant to each other planets and also revolve around the sun.
