How many gram-equivalents of NaOH are required to neutralise 25 cm3 of a decinormal HCl solution?
0.00125
0.0025
0.0050
0.025
Ammonium acetate which is 0.01 M, is hydrolysed to 0.001 M concentration. Calculate the change in pH in 0.001 M solution, if initially pH = pKa
5
10
100
1
Find the correct equation
E2 - E1 - H2 + H1 = n2RT - n1RT
E2 - E1 - H2 - H1 = n2RT - n1RT
H2 - H1 - E2 + E1 = n2RT - n1RT
H2 - H1 - E2 - E1 = n2RT - n1RT
Reaction for the formation of NaCl is
Na(g) + Cl2(g) → NaCl(s)
Na(s) + Cl2(g) → NaCl(s)
Na(g) + Cl2(g) → NaCl(s)
Na(g) + Cl2(g) → NaCl(g)
Which of the ions is colourless inspite of the presence of unpaired electrons ?
La3+
Eu3+
Gd3+
Lu3+
C.
Gd3+
Gadolinium does not absorb light in the visible region of the spectrum, hence it is colourless inspite of the presence of 7 unpaired electrons.
Being colourless, it is sometimes used as a support for other rare earth phosphors and luminesce as it will not quench their intense colours.