Answer: Amount of Gallium = 0.127g
Explanation:
Electrolysis equation is:
Ga3+ + 3e- ------> Ga
To calculate the charge
t = 40.0 min = 40.0 x 60 s = 2400 s
time, t = 2400s
Q = I*t =
= 0.22A x 2400s
= 528 C
1 mol of Ga requires 3 mol of electron
1 mol of electron = 1 Faraday =96485 C
So,1 mol of Ga requires 96485x 3= 289455 C
mol of Gallium = 528/289455 = 0.00182 mol
Molar mass of Ga = 69.72 g/mol
mass of Ga = number of moles x molar mass
= 0.00182mol * 69.72
g/mol
= 0.127g
or you can use this direct formula
m=(current*time/Faraday's)*(molar mass/no of electrons transferred)
keeping in mind Ga3+ + 3e- → Ga
n=3
m=(It/F)*(mew/n)
m =(0.22 x 2400/96485) x (69.72/3)
m=0.127 g
Answer:
B. materials change their properties.
Explanation:
In a chemical change, materials often change their properties because a re-arrangement of atoms takes place.
A chemical change is one in which new kind of matter is formed.
It is always accompanied by energy changes.
- Chemical changes are not reversible.
- They lead to the production of new kinds of matter
- It involves mass changes
- Requires considerable amount of energy
Answer:
¿Cuál es la reaccion quimica de la respiracion celular?
La respiración celular es una reacción exergónica, donde parte de la energía contenida en las moléculas de alimento es utilizada por la célula para sintetizar ATP. ... Aproximadamente el 40% de la energía libre emitida por la oxidación de la glucosa se conserva en forma de ATP.
Explanation:
Answer:
0.459 mol
Explanation:
M(H2SO4) = 2*1 + 32 +4*16 = 98 g/mol
45.0 g * 1 mol/98 g = 0.459 mol
In the given question we need to convert 0.075 meter into centimeter. For this purpose we need to know the relation between meter and centimeter. Then only this problem can be solved and the correct answer reached.
Now we know that
1 meter = 100 centimeter
Then
0.075 meter = [(100/1) * 0.075] centimeter
We know that any number when divided by 1 gives the same number.
So
0.075 meter = (100 * 0.075) centimeter
= (100 * 75/1000) centimeter
= (7500/1000) centimeter
= (75/10) centimeter
= 7.5 centimeter.
So from all the given options the correct answer to the question is 7.5 centimeter.