To get the empirical formula of this compound, we take a basis of 100 grams which means each percentage is equivalent to 1 gram. Hence there is 32.39 grams sodium, 22. 53 grams sulfur and 45.07 grams oxygen. We convert each mass to their moles by dividing by their respective molar mass. Na: 1.408, S:0.704 and O:2.82. divide each with the lowest: Na: 2: S: 1 and O:4. Hence the formula is Na2SO4.
Answer:
Tom is correct. The rate of reaction of Crystal violet and NaOH is first order with respect to NaOH, hence, a higher concentration of NaOH corresponds to a higher rate of reaction; a faster reaction.
This means the speed of cleaning depends on the concentration of the lye used.
Explanation:
The reaction between Crystal violet and NaOH, represented as
CV⁺ + OH⁻ → CVOH
It is a reaction that is know to turn the violet colour of the crystal violet colourless.
The rate of the reaction is also known to be second order; first order with respect to Crystal violet and first order with respect to NaOH.
This means that the rate of reaction is directly proportional to the concentration of NaOH provided all other parameters such as the rate constant and the concentration of Crystal violet are constant.
Hence, the reaction becomes faster with an increased concentration of NaOH.
So, Tom is right, concentrated lye solution would remove the stain faster.
Bob is wrong.
Hope this Helps!!!
Atomic mass silicon = 28.085 u
1 mol Si ---------------- 28.085 g
? ------------------------ 245 g
245 x 1 / 28.085 => 8.72 mol
answer A
Answer:
n = 0.0814 mol
Explanation:
Given mass, m = 35.7g
The molar mass of Tin(IV) bromate, M = 438.33 g/mol
We need to find the number of moles of bromine. We know that,
No. of moles = given mass/molar mass
So,
So, there are 0.0814 moles of bromine in 35.7g of Tin(IV) bromate.
For the purpose we will here use the ideal gas law:
p×V=n×R×T
V= ?
n = 0.5 moleT= 273.15 K (at STP)
p= 101.325 kPa (at STP)
R is universal gas constant, and its value is 8.314 J/mol×K
Now when we have all necessary date we can calculate the number of moles:
V=nxRxT/p
V=0.5x8.314x273.15/101.325= 11.2 L = 11200 mL
Answer: D.
