Hey There!
At neutralisation moles of H⁺ from HCl = moles of OH⁻ from Ca(OH)2 so :
0.204 * 42.8 / 1000 => 0.0087312 moles
Moles of Ca(OH)2 :
2 HCl + Ca(OH)2 = CaCl2 + 2 H2O
0.0087312 / 2 => 0.0043656 moles ( since each Ca(OH)2 ives 2 OH⁻ ions )
Therefore:
Molar mass Ca(OH)2 = 74.1 g/mol
mass = moles of Ca(OH)2 * molar mass
mass = 0.0043656 * 74.1
mass = 0.32 g of Ca(OH)2
Hope that helps!
Answer:
B They move because of the convection currents in the mantle.
The most eletronegative elements are to the right of the periodic table. The electronegativities increase as you move right.
Fluorine and Chlorine are the highest.
Fluorine is 4.0
Chlorine is 3.0
Fluorine is the answer.
Answer:
zince chloride will be formed and hydrogen gas will be librated.
Explanation:
When dilute HCl is added to zinc pieces, a rection will takes place as follows :

It means that zinc chloride will form when zinc reacts with dilute HCL. Also hydrogen gas will produced.
As zinc is more reactive than hydrogen, it displaces hydrogen from its solution and forms zinc chloride. The form product is white in color and H₂ is an odorless gas.
Hence, zince chloride will be formed and hydrogen gas will be librated.
C) Tc-99 is a radioactive isotope also known as radioisoptope.