the answer is wind, hope i helped
Answer:
The molar mass of the unknown gas is 392 g/mole
Explanation:
Firstly we write out the parameters
Volume of the gas X that effuse for 105 s = 1.0 L
Volume of the O₂ gas that effuse for 30 s = 1.0 L
Molar mass of O₂ = 32 g/mole
Rate of effusion of the gas X = 1.0 L/105 s = 0.0095 L/s
Rate of effusion of O₂ gas = 1.0 L/30 s = 0.033 L/s
Graham's law of effusion states that
Therefore we have
or Molar mass of X = 
g/mole = 391.99 g/mole
The molar mass of the unknown gas is 391.99 g/mole ≈ 392 g/mole
Answer: Option (c) is the correct answer.
Explanation:
Entropy is defined as the degree of randomness. This means that more is the number of collisions taking place between atoms of a substance more will be the randomness.
Therefore, more will be the entropy of substance. We cannot measure the entropy but we can measure the change in entropy of a substance.
A thermometer is a glass tube that contains a liquid column generally mercury, and it is usually used to measure the temperature of human body.
A calorimeter is a device or apparatus that is used in a chemical reaction to measure the amount of heat involved.
Therefore, we can conclude that the student can't measure entropy directly, only an entropy change.
Answer:
- Absorbance of sample solution = 1.21
- Absorbance of reagent blank = 0.205
Explanation:
In order to solve this problem we need to keep in mind the <em>Lambert-Beer law</em>, which states:
Where ε is the molar absorption coefficient, b is the length of the cuvette, and C is the concentration.
By looking at the equation above we can see that if ε and C are constant; and b is 5 times higher (5.00 cm vs 1.00 cm) then the absorbance will be 5 times higher as well:
- Absorbance of sample solution = 0.242 * 5 = 1.21
- Absorbance of reagent blank = 0.041 * 5 = 0.205
ANSWER
option B
EXPLANATION
Firstly, we will need to define the standard heat of formation
The standard heat of formation is the amount of heat evolved or absorbed when one mole of a compound is completely formed from its constituent elements under standard conditions.
From the options provided, you will see that only option B aligns with the definition of the standard heat of formation.
From the above reaction, you will see that 1 mole of water is formed from hydrogen and oxygen.
Hence, the answer is option B
