Answer:
the answer is d which is soap solution because it's a soap solution that can measure the degree of hardness of a water if the water forms with this soap solution then the water is hard but if the water forms foam with soap then it is soft
Answer:
Increased
Explanation:
We know that the higher the temperature the higher the rate of reaction. This implies that as the temperature is increased, a reaction tends to proceed faster.
This follows from the collision theory, the higher the temperature, the higher the energy of the reacting particles hence they collide with each other faster and more effectively.
Thus the rate of reaction( or reaction time) for the carton of milk on the counter was increased.
Answer:
The pencil box is too far away from the magnet to make it move.
Explanation:
The most likely scenario here is that the pencil box is too far away from the magnet to make it move.
A magnet has a force field around it which dictates the region where magnetic influences can be felt when a magnetic body is brought near it.
Outside the force field, a magnet has no effect on a magnetic body.
- Since the magnet is not attracting or repelling the metallic box of pencils, they most be located outside the field of force of the magnet.
- When they are within the force field, repulsion or attraction occurs and the field draws the metal to itself or repel.
Objects that are far away from a magnetic source will feel no effect of the force field of a bar magnet.
a. 43.1 g
b. 38.2%
<h3>Further explanation</h3>
Given
32.5 grams of NaOH
Required
The theoretical yield of Na₂CO₃
The percent yield
Solution
Reaction
2NaOH(s) + CO₂(g) → Na₂CO₃(s) + H₂O(l)
mol NaOH :
= mass : MW
= 32.5 : 40 g/mol
= 0.8125
mol Na₂CO₃ from the equation :
= 1/2 x mol NaOH
= 1/2 x 0.8125
= 0.40625
a.
Mass Na₂CO₃ :
= mol x MW Na₂CO₃
= 0.40625 x 106 g/mol
= 43.0625≈43.1 g
b. % yield = (actual/theoretical) x 100%
%yield = 16.45/43.1 x 1005
%yield = 38.17%≈38.2%
