Answer:
27.60 g urea
Explanation:
The <em>freezing-point depression</em> is expressed by the formula:
In this case,
- ΔT = 5.6 - (-0.9) = 6.5 °C
m is the molality of the urea solution in X (mol urea/kg of X)
First we<u> calculate the molality</u>:
- 6.5 °C = 7.78 °C kg·mol⁻¹ * m
Now we<u> calculate the moles of ure</u>a that were dissolved:
550 g X ⇒ 550 / 1000 = 0.550 kg X
- 0.84 m = mol Urea / 0.550 kg X
Finally we <u>calculate the mass of urea</u>, using its molecular weight:
- 0.46 mol * 60.06 g/mol = 27.60 g urea
Answer:
The coefficient of Ca(OH)2 is 1
Explanation:
Step 1: unbalanced equation
Ca(OH)2 + HNO3 → Ca(NO3)2 + H2O
Step 2: Balancing the equation
On the right side we have 2x N (in Ca(NO3)2 ) and 1x N on the left side (in HNO3). To balance the amount of N on both sides, we have to multiply HNO3 by 2.
Ca(OH)2 + 2HNO3 → Ca(NO3)2 + H2O
On the left side we have 4x H (2xH in Ca(OH)2 and 2x H in HNO3), on the right side we have 2x H (in H2O). To balance the amount of H on both sides, we have to multiply H2O on the right side, by 2.
Now the equationis balanced.
Ca(OH)2 + 2HNO3 = Ca(NO3)2 + 2H2O
The coefficient of Ca(OH)2 is 1
- <span>The </span>speed of light<span> is the </span>speed<span> electromagnetic waves travel. The </span>speed of light<span> is 3.0 x 108 m/s in space. The </span>speed of light<span> is the same in all matter. The </span>speed<span> of higher frequency </span>light <span>slows down more than lower frequency </span>light<span> in matter.</span>
Answer:
This question appears incomplete
Explanation:
There is no such element known as "Ballardium (Bu)" in the periodic table. However, there are elements with a bit of similarity in spellings and pronunciation such as Beryllium (Be) which is found in group 2 (meaning it is an alkali earth metal), Berkelium (Bk) which is an actinide (meaning it is radioactive) and Vanadium (V) which is found in group 5 of the periodic table (meaning it's a transition metal).
Explanation:
The reaction equation will be as follows.

Hence, moles of Na = moles of electron used
Therefore, calculate the number of moles of sodium as follows.
No. of moles = 
=
(as 1 kg = 1000 g)
= 195.65 mol
As, Q =
where F = Faraday's constant
= 
=
mol C
Relation between electrical energy and Q is as follows.
E = 
Hence, putting the given values into the above formula and then calculate the value of electricity as follows.
E = 
= 
= 
As 1 J =
kWh
Hence,
kWh
= 3.39 kWh
Thus, we can conclude that 3.39 kilowatt-hours of electricity is required in the given situation.