Question: Given the balanced equation representing a reaction:
2H2 + O2 ==>2H2O
What is the total mass of water formed when 8 grams of hydrogen reacts completely with 64 grams of oxygen?
(1) 18 g (3) 56 g
(2) 36 g (4) 72 g
Answer:
"72 gram" is the total mass of water formed when 8 grams of hydrogen reacts completely with 64 grams of oxygen
Explanation:
We will do stoichiometry in this kind of problem:
Therefore, the total mass of water formed is 72 g.
Answer:
a zinc is the most reactive
Explanation:
For the given values of we will have the values of as follows.
As,
Therefore,
= 2.15, = 7.20
= 12.38
Now, at pH 6.50
;
At pH = 2.15;
;
At pH 7.20;
;
Hence, we can conclude that most abundant species is and the second most abundant species is .
The volume of a balloon f a gas at 842 mm Hg and -23 celsius if it’s volume is 915 milliliters at a pressure of 1170 mm Hg And a temperature of 24 celsius is 0.22 litres
Explanation:
Data given:
Initial volume of the balloon having gas V1= 915ml OR 0.195 L
initial pressure of the gas P1= 1170 mm Hg OR 1.53 atm
initial temperature of the gas T1 = 24 celsius or 273.15 + 24 = 297.15 K
Final pressure of the gas P2 = 842 mm Hg or 1.10 atm
final temperature of the gas T2 = -23 degrees or 273.15 - 23 = 250.15 K
Final volume at final temperature and pressure V2=?
The formula used is of Gas Law:
=
V2 =
putting the values in the equation:
V2 =
V2 = 0.22 litres is the volume
The volume is 0.22 litres at a pressure of 1170 mmHg and temperature of -23 degrees.
Answer:
0.09375M
Explanation:
There are two methods of going about this, either we use dilution formula (easiest and fastest) or we solve through molarity.
Using dilution formula,
C2 (H2SO4) = ?
C1 (NaOH) = 0.25M
V2 (H2SO4) = 20cm³
V1 (NaOH) = 15cm³
However we can solve using molarity method
Equation of reaction =
2NaOH + H2SO4 ====》 Na2SO4 + 2H2O
O.25M of NaOH = 1000cm³
X moles = 15cm³
X = (0.25 * 15) / 1000
X = 0.00375 moles is present in 15cm³ of NaOH
From equation of reaction,
2 moles of NaOH requires 1 mole of H2SO4
Therefore
0.00375 / 2 = 0.001875 moles is present in H2SO4
From the reaction,
0.00187 moles of H2SO4 = 20 cm³
X moles = 1000cm³
X = (0.00187*1000) / 20 = 0.09375M