Answer:
A solution is made by dissolving 4.87 g of potassium nitrate in water to a final volume of 86.4 mL solution. The weight/weight % or percent by mass of the solute is :
<u>2.67%</u>
Explanation:
Note : Look at the density of potassium nitrate in water if given in the question.
<u><em>You are calculating </em></u><u><em>weight /Volume</em></u><u><em> not weight/weight % or percent by mass of the solute</em></u>
Here the <u>weight/weight % or percent by mass</u> of the solute is asked : So first convert the<u> VOLUME OF SOLUTION into MASS</u>
Density of potassium nitrate in water KNO3 = 2.11 g/mL
Density = 2.11 g/mL
Volume of solution = 86.4 mL
Mass of Solute = 4.87 g
Mass of Solution = 183.2 g
w/w% of the solute =
w/w%=2.67%
Answer:
petroleum,natural gas,lime stone, coal,water,acetylene etc.
Answer:
a. HCl + NH₃ ⇄ NH₄Cl
b. KOH + NH₄⁺ ⇄ K⁺ + NH₃ + H₂O
Explanation:
A buffer system is made by a weak base (ammonia, NH₃) and its conjugate acid (ammonium ion NH₄⁺ coming from ammonium chloride NH₄Cl). Its function is to resist abrupt changes in the pH when acids or bases are added.
a. When aqueous hydrochloric acid is added, it reacts with the base of the buffer. The corresponding equation is:
HCl + NH₃ ⇄ NH₄Cl
b. When aqueous potassium hydroxide is added, it reacts with the acid of the buffer. The corresponding equation is:
KOH + NH₄⁺ ⇄ K⁺ + NH₃ + H₂O
The correct answer is A.
Gravitational force will attract any object with mass. It's why you're not floating in the air right now, but rather making contact with the ground. At the same time, since you have mass, you're also attracting other objects right now with gravitational force.