Suppose you are collecting a gas over water at 23 oC and obtain a pressure reading of 785.8 mm Hg. If the vapor pressure of water is 21.1 mm Hg at the collection temperature, what is the pressure of the collected gas

764.7 mmHg

Explanation:

Step 1: Given data

Total pressure of the gaseous mixture (P): 785.8 mmHgPartial pressure of water vapor (pH₂O): 21.1 mmHgPartial pressure of the gas collected (pGas): ?

Step 2: Calculate the partial pressure of the gas collected

The total pressure of the gaseous mixture is equal to the sum of the gas collected and the water vapor.

P = pH₂O + pGas

pGas = P - pH₂O

pGas = 785.8 mmHg - 21.1 mmHg = 764.7 mmHg

Idid the calculation and i get 875,000,000 which can be written as 8.75 x 10^6?

the catch is that the top numbers are atomic masses the bottom numbers are the numbers of protons and electrons in an uncharged atom. they are the number of that atoms as you would find them on the periodic table. further, the numbers on the left are used to determine the missing numbers on the right

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer