I think that is A is the answer.
First, we write the reaction equation:
2KI + PbNO₃ → K₂NO₃ + PbI₂
The molar ratio of KI to PbNO₃ is 2 : 1
Moles of PbNO₃ present:
Moles = concentration (M) x volume (dm³)
= 0.194 x 0.195
= 0.038
Moles of KI required = 2 x 0.038 = 0.076 moles
concentration = moles / volume
volume = moles / concentration
= 0.076 / 0.2
= 0.38 L = 380 ml
Answer:Protons are positively charged is the correct statement about an atom
I've also corrected the other statements
Atoms contain protons and neutrons in their nucleus
Neutrons posses no charge and are neutral
The nucleon number is the total number of protons and neutrons in a nucleus
Answer:
Incomplete
Explanation:
I wouldn't say that a scientific theory is wrong.
It is the best we have at the time, based on all available knowledge .
As each new discovery is made, scientists modify the theory to fit the new knowledge.
The scientific method is a never-ending process.
Answer:
the ph of an aqueous solution of sulphuric acid which is 5*10^5 mol in concentration is basic in nature
