Calculate the [H +] in a 0.028 M solution of HCN, K a = 6.2 × 10 –10. a.
1.0 × 10–7 M
b.
4.2 × 10–6 M
c.
1.7 × 10–11 M
d.
8.3 × 10–6 M
e.
none of these

Select the correct answer. you have a nightlight plugged into an outlet in the hallway, which uses 3.5 watts when plugged in. if the house circuit provides 120.0 volts, what is the current through this bulb?

Evaluate this exponential expression,8. (2 + 3)2 – 42

1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false