Answer:
The correct option is;
True
Explanation:
The noble gases are the group 18 elements, all of which are monoatomic gases, located in the extreme right of the periodic table. Due to their filled outermost or valence shells,and their nonreactive nature, the noble gases where initially known as inert gases.
The noble gases have very low melting points and boiling points as hey have very weak inter atomic forces between their atoms such that they all appear as gases under standard atmospheric temperature and pressure conditions.
The balanced chemical equation that illustrates this reaction is:
<span>C2H4 + 3O2 --> 2CO2 + 2H2O
</span>
From the periodic table:
mass of carbon = 12 grams
mass of hydrogen = 1 gram
Therefore:
molar mass of C2H4 = 12(2) + 4(1) = 24 + 4 = 28 grams
number of moles = mass / molar mass
number of moles of C2H4 = 54.7 / 28 = 1.95 moles
From the balanced equation above:
3 moles of oxygen are required to react with one mole of C2H4, therefore, to know the number of moles required to react with 1.95 moles of C2H4, all you have to do is cross multiplication as follows:
number of oxygen moles = (1.95*3) / 1 = 5.85 moles
Answer:
These are three different forms of expressing a volume of 2000 ml:
Explanation:
The expression 2000 ml means 2000 mililiters and convey three important informations:
- The unit, which is mililiter (1 ml = 1 / 1,000 liter)
- The magnitude, which is 2000
- The precision: the zeros to the right of the figure 2 are not significative, so this magnitue is precise only to the thousands units. This means, that the measure could be between 1500 and 2499 (ml).
You might express the same volume with a different unit, e.g. liter, and in a different way (using scientific notation).
<u>1) Changing the unit.</u>
To change ml to liter you must multiply for the conversion factor:
Thus, 2000 ml is equal to:
- 2000 ml × 1 liter / 1,000 ml = 2 liter
<u>2) Using scientific notation:</u>
You change the number to a power of ten, using a decimal greater than or equal to 1 and less than 10.
For 2000 the decimal is 2. and the power of ten is 3 (for the three zeros after the 2):
