I think the given is 3 g sample of NaHCO3. then if it will be reacted with an acid, it will produce H2CO3.
so the reaction NaHCO3 + HCl --> NaCl + H2CO3
mas of H2CO3 = 3 g NaHCO3 ( 1 mol NaHCO3 / 84 g ) ( 1 mol H2CO3 / 1 mol NaHCO3) ( 62.03 g / 1 mol )
mass of H2CO3 = 2.22 g H2CO3
<h2>Answer : Option C) Joseph is observing the color of the reaction mixture to see whether proteins are present in the given solution.</h2><h3>Explanation :</h3>
An example of qualitative observation is the one where one uses the five senses to identify the changes in the reaction.
Here, when Joseph is studying a reaction mixture he is trying to observe a color change which will confirm that there is proteins present in the reaction mixture or not If there is a color change observed then it will confirm the presence of proteins.
Usually qualitative observations are those which can be easily predicted by using five senses.
Answer is: the partial pressure of the helium gas is 0.158 atm.
p(mixture) = 0.48 atm; total pressure.
m(H₂) = 1.0 g; mass of hydrogen gas.
n(H₂) = m(H₂) ÷ M(H₂).
n(H₂) = 1.0 g ÷ 2 g/mol.
n(H₂) = 0.5 mol; amount of hydrogen.
m(He) = 1.0 g; mass of helium.
n(He) = 1 g ÷ 4 g/mol.
n(He) = 0.25 mol; amount of helium.
χ(H₂) = 0.5 mol ÷ 0.75 mol.
χ(H₂) = 0.67; mole fraction of hydrogen.
χ(He) = 0.25 mol ÷ 0.75 mol.
χ(He) = 0.33; mole fraction of helium.
p(He) = 0.33 · 0.48 atm.
p(He) = 0.158 atm; the partial pressure of the helium gas.
Answer:
Total pressure at equilibrium is 0.2798atm.
Explanation:
For the reaction:
H₂S(g) ⇄ H₂(g) + S(g)
Kp is defined as:

If initial pressure of H₂S is 0.150 atm, equilibrium pressures are:
H₂S(g): 0.150atm - x
H₂(g): x
S(g): x
Replacing in Kp:

X² = 0.1251 - 0.834X
X² + 0.834X - 0.1251 = 0
Solving for X:
X = -0.964 → False solution: There is no negative pressures
X = 0.1298
Thus, pressures are:
H₂S(g): 0.150atm - 0.1298atm = <em>0.0202atm</em>
H₂(g): <em>0.1298atm</em>
S(g): <em>0.1298atm</em>
Thus, total pressure in the container at equilibrium is:
0.0202atm + 0.1298atm + 0.1298atm = <em>0.2798atm</em>