How much atomic mass does Osmium have
1 answer:
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The initial temperature is 137.34 °C.
<u>Explanation:</u>
As the specific heat formula says that the heat energy required is directly proportional to the mass and change in temperature of the system.
Q = mcΔT
So, here the mass m is given as 23 kg, the specific heat of steel is given as c = 490 J/kg°C and the initial temperature is required to find with the final temperature being 140 °C. Also the heat energy required is 30,000 J.
ΔT =
ΔT =
Since the difference in temperature is 2.66, then the initial temperature will be
Final temperature - Initial temperature = Change in temperature
140-Initial temperature = 2.66
Initial temperature = 140-2.66 = 137.34 °C
Thus, the initial temperature is 137.34 °C.
Answer: 250 ml of stock solution with molarity of 12.0 M is measured using a pipette and 250 ml of water is added to volumetric flask of 500 ml to make the final volume of 500 ml.
Explanation:
According to the dilution law,
where,
= concentration of stock solution = 12.0 M
= volume of stock solution = ?
= concentration of diluted solution= 6.00 M
= volume of diluted acid solution = 500 ml
Putting in the values we get:
Thus 250 ml of stock solution with molarity of 12.0 M is measured using a pipette and 250 ml of water is added to volumetric flask of 500 ml to make the final volume of 500 ml.
Answer:
( Naphthalene )
Explanation:
Given that:
4.50 g of a Compound X is made up of Carbon , Hydron and Oxygen
It's molecular molar mass = 128 g/mol
Compound X undergoes combustion reaction and the product yield :
CO_2 with mass 15.47g and :
H_2O with mass 2.53 g
The objective is to use this information to determine the molecular formula of X.
We all know that ; number of moles = mass/molar mass
where the molar mass of H_2O is 18 g/mol
number of moles of H_2O product = 2.53 g/18 g/mol
number of moles of H_2O product = 0.1406 moles
Also; the molar mass of CO_2 product = 44 g/mol
number of moles of CO_2 product = 15.47g/ 44 g/mol
number of moles of CO_2 product = 0.3516 moles
number of moles of Compound X in the reactant side= 4.50 g /128 g/mol
number of moles of Compound X n the reactant side= 0.03516 moles
Now; number number of moles of CO_2 in reactant = 0.3516 moles/0.03516 moles
Now; number number of moles of CO_2 in reactant = 10
number of moles of H_2O reactant = 0.1406 moles × 2/0.03516
number of moles of H_2O reactant = 7.997 ≅ 8
Since we said the Compound X is known to be made of Carbon C , Hydrogen H and Oxygen O
Then the molecular formula can be written as :
In order to find the x; we have
128 = (12 × 10 + 1 × 8 + 16 × x)
128 = 120 + 8 + 16x)
128 = 128 + 16 x
128 - 128 = 16 x
0 = 16 x
x = 0/16
x = 0
As x = 0 ; hence there are no oxygen present in the reaction
Thus; the molecular formula of Compound X = which is also known as Naphthalene