Answer:
Scandium
Explanation:
Mendeleev played an important role in the development of the modern periodic table. His periodic table was filled with gaps. He said that these gaps were elements that were yet to be discovered. He rightly predicted many elements which have now been discovered and fitted in their proper places in the periodic table.
He used the prefix ''eka'' to refer to elements whose properties were alike but were yet to be discovered at that time.
The compound named ekaboron which he predicted to have an atomic weight between 65 (zinc) and 75 (arsenic) with a valence similar to aluminum was later discovered in 1879 and properly named scandium.
Answer:
4.33 L
Explanation:
Assuming ideal behaviour and that all 0.300 moles of gas reacted, we can solve this problem using Avogadro's law, which states that at constant temperature and pressure:
Where in this case:
We <u>input the given data</u>:
- 2.16 L * 0.601 mol = V₂ * 0.300 mol
And <u>solve for V₂</u>:
<u>Answer:</u>
2400 mL
<u>Explanation:</u>
According to this equation, the stoichiometric ratio between 
and 
for the complete reaction is 1:2.
We know that the number of moles of can be calculated using the mole formula. (<em>number of moles = mass / molar mass</em>)
Moles of Calcium = 
= 1.5 mol
So the moles of = 
= 3.0 mol
<em>Volume of HCl solution = Moles of HCl/ concentration of HCl</em>
Volume of HCl solution = 
= 2400 mL
1. True
2. False
3. False
4. True
5. True
6. True
7. All of the above
8. According to their reactivity with other substances
9. Standard temp and pressure
10. Flush your eyes in the eye flush for 15-20 minutes
