Answer:
At 3 mmHg and 50°C water exists as a <em><u>gas</u></em>.
Answer : The correct option is, (D) CO₂, BCl₃, and Fe³⁺
Explanation :
According to the Lewis concept, an acid is defined as a substance that accepts electron pairs and base is defined as a substance which donates electron pairs.
(a) 
It is a Lewis-acid because it can accepts electron pairs.
(b) 
It is not a Lewis-acid because it can not accepts electron pairs but it is a base because it can donates and accept hydrogen ion.
(c) 
It is a Lewis-acid because it can accepts electron pairs because it has an incomplete octet and an empty 2p orbital.
(d) 
It is a Lewis-acid because it can accepts electron pairs.
Hence, the ions which behave as Lewis acids are, CO₂, BCl₃, and Fe³⁺
3.4 X 10^-2 because you start your equation with 2.5g in your (what we call train tracks). Then you have to find the GFM (gram formula mass) of KCl (potassium chloride). You find this by adding the average atomic mass of each element. Potassium's is 39.10 and Chlorine's is 35.45 which gives you a total of 74.55 grams per mol. so now that you have found the GFM you plug that number into the diagonal bottom in order to cancel the gram units. Then you would place 1 mol KCl on top because that is the unit you want. Finally you will divide your original 2.5 by the GFM of 74.55 to get an answer of 0.033534 mol KCl... but since sig figs matter your final answer will be 3.4 X 10^-2
Earth, Air, Water, and Fire