Answer:
See explanation
Explanation:
From left to right, the oxides across period 3;
i) Period 3 oxides all appear white in colour. They are all crystalline solids and their melting points decrease from left to right.
ii) The volatility of period 3 oxides increases from left to right across the periodic table
iii) The metallic oxides on the right hand side adopt giant ionic structures. Silicon oxide which is in the middle of the period forms a giant covalent structure. Oxides of other elements towards the right hand side form molecular oxide structures.
iv) The acidity of oxides of period 3 increases from left to right. Metals on the left hand side form basic oxides while non-metals on the right hand side form acidic oxides. The oxide of aluminium in the middle is amphoteric.
v) The oxides of period 3 elements do not conduct electricity. However, the metallic oxides on the lefthand side conduct electricity in molten state. The non-metallic oxides on the right hand side are molecular hence they do not conduct electricity under any circumstance.
Answer:
-195.8º < -191.5º < 100º
Explanation:
Water, or H20, starts boiling at 100ºC.
Nitrogen, or N2, starts boiling at -195.8ºC.
Carbon monoxide, or C0, starts boiling at -191.5ºC.
When we place these in order from decreasing boiling point:
-195.8º goes first, then -191.5º, and 100º goes last.
<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>
