<span>Pre-1982 definition of STP: 37 g/mol
Post-1982 definition of STP: 38 g/mol
This problem is somewhat ambiguous because the definition of STP changed in 1982. Prior to 1982, the definition was 273.15 K at a pressure of 1 atmosphere (101325 Pascals). Since 1982, the definition is 273.15 K at a pressure of exactly 100000 Pascals). Because of those 2 different definitions, the volume of 1 mole of gas is either 22.414 Liters (pre 1982 definition), or 22.71098 liters (post 1982 definition). And finally, there's entirely too many text books out there that still use the 35 year obsolete definition. So let's solve this problem using both definitions and you need to pick the correct answer for the text book you're using.
First, determine how many moles of gas you have. Just simply divide the volume you have by the molar volume.
Pre-1982: 2.1 / 22.414 = 0.093691443 moles
Post-1982: 2.1 / 22.71098 = 0.092466287 moles
Now determine the molar mass. Simply divide the mass by the moles. So
Pre-1982: 3.5 g / 0.093691443 moles = 37.35666667 g/mol
Post-1982: 3.5 g / 0.092466287 moles = 37.85163333 g/mol
Finally, round to 2 significant figures. So
Pre-1982: 37 g/mol
Post-1982: 38 g/mol</span>
Answer:
7.28 mol Na2SO4
Explanation:
Since it is already in moles, all we have to do is use a molar ratio
A molar ratio is the proportions of reactants and products using the balanced equation. When writing a mole ratio, the given information must cross out with the right thing.
7.28 mol H2SO4 * 1 mol Na2SO4/1 H2SO4 = 7.28 mol Na2SO4
*notice how the H2SO4 crosses out
The reaction will produce solid copper and aluminium chloride salt.
Explanation:
Copper chloride (CuCl₂) in solution will react with aluminium to form solid cooper and aluminium chloride (AlCl₃).
3 CuCl₂ (aq) + 2 Al (s) → 3 Cu (s) + 2 AlCl₃ (aq)
Learn more about:
numerical problems with copper chloride and aluminium
brainly.com/question/8827783
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Answer:
They are emitted from heated objects
Explanation:
When objects are heated, they emit light at all wavelengths thereby forming a continuous spectrum. Electromagnetic radiation of all wavelengths and colours are usually represented in such spectrum. A thermal spectrum is quite a simple spectrum since it depends on temperature.
