Answer : The molecular weight of a gas is, 128.9 g/mole
Explanation : Given,
Density of a gas = 5.75 g/L
First we have to calculate the moles of gas.
At STP,
As, 22.4 liter volume of gas present in 1 mole of gas
So, 1 liter volume of gas present in 
mole of gas
Now we have to calculate the molecular weight of a gas.
Formula used :
Now put all the given values in this formula, we get the molecular weight of a gas.
Therefore, the molecular weight of a gas is, 128.9 g/mole
This is what I found!!! I hope this helps!!!!
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Answer:</h2>
ZINC
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Explanation:</h2>
<em>To identify the element based on the informartion given, we have to find the molar mass since this mass is unique to each element.</em>
Molar mass = mass ÷ moles
<em>We already know the mass based on the question, as such we now need to find the # of moles.</em>
Since 1 mole contains 6.02214 × 10²³ atoms
then let x moles contain 4.19 × 10²³ atoms <em>(given in the question)</em>
<em> </em><em> </em> ⇒ x = (4.19 × 10²³ atoms × 1 mol) ÷ 6.02214 × 10²³ atoms
x = 0.69577 mol
<em>Now that we have the moles we can substitute it into the molar mass equation and solve for the molar mass.</em>
⇒ molar mass = 45.6 g ÷ 0.69577 mol
⇒ molar mass ≈ 65.54 g/mol
This molar mass is closest to that of ZINC.
Answer:
<em>When salt is dissolved in water</em>, many physical properties change, among them the so called colligative properties:
- The vapor pressure of water decreases,
- The boiling point increases,
- The freezing point decreases, and
- Osmotic pressure appears.
Explanation:
Colligative properties are the physical properties of the solvents whose change is determined by the number of particles (moles or ions) of the solute added.
The colligative properties are: vapor pressure, boiling point, freezing point, and osmotic pressure.
<u>Vapor pressure</u>:
The vapor pressure is the pressure exerted by the vapor of a lquid over its surface, in a closed vessel.
The vapor pressure increases when a solute is added, because the presence of the solute causes less solvent molecules to be near the surface ready to escape to the vapor phase, which means that the vapor pressure is lower.
<u>Boiling point</u>:
The boiling point is the temperature at which the vapor pressure of the liquid equals the atmospheric pressure. Since we have seen that the vapor pressure of water decreases when a solute occupies part of the surface, now more temperature will be required for the water molecules reach the atmospheric pressure. So, the boiling point increases when salt is dissolved in water.
<u>Freezing point</u>:
The freezing point is the temperarute at which the vapor pressure of the liquid and the solid are equal. Since, the vapor pressure of water with salt is lower than that of the pure water, the vapor pressure of the liquid and solid with salt will be equal at a lower temperature. Hence, the freezing point is lower (decreases).
<u>Osmotic pressure</u>:
Osmotic pressure is the additional pressure that must be exerted over a solution to make that the vapor pressure of the solvent in the solution equals the vapor pressure of the pure solvent. This additional pressure is proportional to the concentration of the solute: the higher the salt concentration the higher the osmotic pressure.
Answer:
Decreasing the temperature will shift the equilibrium leftwards towards reactants.
Explanation:
Hello!
In this case, since the reaction between chromate anions and hydrogen ions yields dichromate anions, water and heat, we can infer this is an exothermic reaction by which heat is released (remember in endothermic reactions heat is absorbed as a reactant), it means that considering the LeChatelier’s which states that increasing the temperature of an exothermic reaction shifts the equilibrium leftwards since heat is a product, otherwise (decreasing the temperature) the equilibrium will be shifted rightwards.
Therefore, decreasing the temperature is the perturbation that will shift the equilibrium leftwards towards the reactants.
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