The pH value can be measured using electrochemical measuring systems, litmus paper, or indicators and colorimeters. The easiest way to take a pH measurement is to use litmus paper or a colorimeter. The advantage of this type of pH measurement is that the pH range is well known and they are easy to apply.
Answer:
Mass of barium sulfate = 8.17 g
Explanation:
Given data:
Mass of sodium sulfate = 4.98 g
Mass of barium sulfate produced = ?
Solution:
Na₂SO₄ + Ba(NO₃)₂ → BaSO₄ + 2NaNO₃
Moles of sodium sulfate:
Number of moles = mass/molar mass
Number of moles =4.98 g / 142.04 g/mol
Number of moles = 0.035 mol
Now we will compare the moles pf sodium sulfate and with barium sulfate.
Na₂SO₄ : BaSO₄
1 : 1
0.035 : 0.035
Mass of barium sulfate:
Mass = number of moles × molar mass
Mass = 0.035 mol ×233.4 g/mol
Mass = 8.17 g
Answer:
C) ball rollinflown a hill
Explanation:
The question asks to identify the endothermic process in the list of options. By way of elimination, we have;
A) condensation of water on a wind shield of a car
Condensation is an exothermic process. That is, heat is given out as the gases change into the liquid state of matter.
B) formation of copper
This is an exothermic process. Capture of electrons by a cation is always exothermic.
C) ball rollinflown a hill
This is the correct option. Energy is absorbed by the ball as it moves on the hill
D) formation of ice from liquid water
Freezing is an example of exothermic reaction. Heat is given off to the surroundings.
E) oxide from copper and oxygen
Formation of metal oxides and most reactions involving oxygen are exothermic reactions,
Answer:
Muscular contractions that moves food along the digestive tract.
