Answer: Event 1 is an example of a physical change and Event 2 is an example of a chemical change.
Explanation: Physical change is one in which there is no change in chemical composition of the substance. There is only a change in phase change.
Chemical change is a change in which there is a change in chemical composition and there might or might not be a phase change.
On Boiling, the water molecules remain bonded in the same form and only covert from liquid to gaseous form, thus is a physical change.
On Rusting of iron nail, the iron changes to iron oxide by combining with oxygen, there is a rearrangement of atoms and thus is a chemical change.
Answer:
Mass of water produced is 22.86 g.
Explanation:
Given data:
Mass of hydrogen = 2.56 g
Mass of oxygen = 20.32 g
Mass of water = ?
Solution:
Chemical equation:
2H₂ + O₂ → 2H₂O
Number of moles of oxygen:
Number of moles = mass/ molar mass
Number of moles = 20.32 g/ 32 g/mol
Number of moles = 0.635 mol
Number of moles of hydrogen:
Number of moles = mass/ molar mass
Number of moles = 2.56 g/ 2 g/mol
Number of moles = 1.28 mol
Now we will compare the moles of water with oxygen and hydrogen.
O₂ : H₂O
1 : 2
0.635 ; 2×0.635 = 1.27
H₂ : H₂O
2 : 2
1.28 : 1.28
The number of moles of water produced by oxygen are less thus it will be limiting reactant.
Mass of water produced:
Mass = number of moles × molar mass
Mass = 1.27 × 18 g/mol
Mass = 22.86 g
Answer:
Signals from the A. Nervous system make the skeletal muscles move.
Answer: 23 liter
Explanation: Im pretty sure
Answer:
How the relative density of a substance is related to the density calculate the density of iron if its relative density is 2 and a density of water is 2gcm -3
R.d= relative density of substance/ relative density of water
R.d= 2/2
R.d= 1gcm-3
Explanation:
