Answer:
69.55 (w/w) %
Explanation:
When NaHCO3 reacts with an acid HA, the reaction that occurs is:
NaHCO3 + HA → H2O + NaA + CO2
<em>Where 1 mole of NaHCO3 produce 1 mole of CO2</em>
<em />
Thus, we need to convert the mass of CO2 to moles using its molar mass (44g/mol). Then, based on the chemical equation, moles of CO2 produced are equal to moles of NaHCO3 in the mixture. With its molar mass -84g/mol- we can find the mass of NaHCO3 and mass percent:
<em>Moles CO2:</em>
0.561g * (1mol / 44g) = 0.01275 moles CO2 = Moles NaHCO3.
<em>Mass NaHCO3:</em>
0.01275 moles * (84g/mol) = 1.071g NaHCO3
<em>Mass percent:</em>
1.071g NaHCO3 / 1.54g sample * 100
<h3>69.55 (w/w) %</h3>
<span>The answer is A. The pump and the plastic are the only ones that create pressure compared to the other choices.
When you exert a force on the pump to a closed object such as plastic, the pressure inside the pump that it gives off makes the plastic full of air. Pressure is defined to be the force per unit area or the stress within a fluid. </span>
Answer:
Mass = 182.4 g
Explanation:
Given data:
Number of moles of Al₂O₃ = 3.80 mol
Mass of oxygen required = ?
Solution:
Chemical equation:
4Al + 3O₂ → 2Al₂O₃
Now we will compare the moles of aluminum oxide and oxygen.
Al₂O₃ : O₂
2 : 3
3.80 : 3/2×3.80 = 5.7
Mass of oxygen:
Mass = number of moles × molar mass
Mass = 5.7 mol × 32 g/mol
Mass = 182.4 g
Adding an atom affect the position of existing atoms and lone pairs by changing the geomertry and <span>changing postion of the lone pairs and atoms so that they are furthest apart. Hope this answers the question. Have a nice day.</span>
Take a look at this and see if you can get an understanding and explain it in oxidation numbers