Answer:
Explanation:
To solve this problem, we need to obtain the number of moles of the solute we desired to prepare;
Number of moles = molarity x volume
Parameters given;
volume of solution = 500mL = 0.5L
molarity of solution = 0.5M
Number of moles = 0.5 x 0.5 = 0.25moles
Now to know the volume stock to take;
Volume of stock =
molarity of stock = 4M
volume =
= 0.0625L or 62.5mL
Answer: Option (b) is the correct answer.
Explanation:
A covalent compound is defined as the compound in which sharing of electrons take place between the combining atoms. Generally, when two or more non-metals chemically combine together the it will lead to the formation of a covalent compound.
For example,
and HCl is also a covalent compound.
And, a compound in which transfer of electrons occur between the combining atoms is known as an ionic compound. Whenever, a metal chemically combines with a non-metal then it will always lead to the formation of an ionic compound.
For example, KI is an ionic compound.
Thus, we can conclude that
and HCl are the two substances which are covalent compounds.
Molarity can be defined as the number of moles of substance dissolved in 1 L of solution.
In the given question ,
number of LiOH moles - 1.495 mol
Dissolved volume - 750 mL
molarity is calculated for 1 L = 1000 mL
In 750 mL - 1.495 mol of LiOH is dissolved
Therefore in 1000 mL - 1.495 mol / 750 mL x 1000 = 1.99 mol
Answer:
K₂CO₃
Explanation:
Given parameters:
Number of moles of K = 0.104mol
Number of moles of C = 0.052mol
Number of moles of O = 0.156mol
Method
From the given parameters, to calculate the empirical formula of the elements K, C and O, we reduce the given moles to the simplest fraction.
Empirical formula is the simplest formula of a compound and it differs from the molecular formula which is the actual formula of a compound.
- Divide the given moles through by the smallest which is C, 0.052mol.
- Then approximate values obtained to the nearest whole number of multiply by a factor to give a whole number ratio.
- This is the empirical formula
Solution
Elements K C O
Number of moles 0.104 0.052 0.156
Dividing by the
smallest 0.104/0.052 0.052/0.052 0.156/0.052
2 1 3
The empirical formula is K₂CO₃
Answer:
At -13
, the gas would occupy 1.30L at 210.0 kPa.
Explanation:
Let's assume the gas behaves ideally.
As amount of gas remains constant in both state therefore in accordance with combined gas law for an ideal gas-

where
and
are initial and final pressure respectively.
and
are initial and final volume respectively.
and
are initial and final temperature in kelvin scale respectively.
Here
,
,
,
and
Hence 



So at -13
, the gas would occupy 1.30L at 210.0 kPa.