Chemistry common errors Flashcards Preview

Chemistry > Chemistry common errors > Flashcards

Flashcards in Chemistry common errors Deck (16)
Loading flashcards...
1
Q

Why is there a lid on containers for chromatography?

A

To prevent evaporation of solvent

2
Q

What information does mass spectroscopy give?

A

Identifies solvents

3
Q

What will the color of methyl orange indication be when solution turns less acidic?

A

It will turn from red to yellow

4
Q

Ammonia + ______ acid = Ammonium nitrate

A

Nitric

5
Q

Why do farmers put ammonium nitrate on their farmland?

A

To help plants grow

6
Q

Does rate of reaction increases at the start of an experiment?

A

No

7
Q

Why is gold used as catalyst in industrial processes?

A

It increases rate of reaction
It is not used up
Only a small amount of it is needed

8
Q

Why is the positive electrode in the cell of electrolysis used up?

A

Because the electrode reacts with oxygen to form carbon dioxide

9
Q

Why is diamond harder than graphite?

A

Because the layers of carbon a times in graphite can slide
There is only weak intermolecular forces between layers
However, in diamond, each carbon atom is covalently bonded to 4 others
So no atom is able to slide

10
Q

Why does graphite conduct electricity but diamond does not?

A

Graphite has delocalized electrons
Which is a charged particle that moves throughout the structure
However, diamond doesn’t have delocalized electrons

11
Q

What is the first step of the question: ‘The student wanted to find the volume of HCl that reacts with a known volume of NaOH’?

A

Measure the volume of NaOH with a graduated pipette

12
Q

What is the use of silver and carbon in ion change resin?

A

Carbon removes chlorine (deemed by some to make to water taste better)
Silver kills bacteria in replacement of chlorine

13
Q

What is the typical unit for bond energy?

A

Kilojoules

14
Q

How do you calculate bond energy change?

A

Bonds broken (energy absorbed) - bonds formed (energy given out)

15
Q

Why can hydrogen be used as a fuel?

A

More energy is needed to build bonds than to break them. The reaction is exothermic and energy is released when hydrogen reacts with oxygen in the air

16
Q

When calculating moles, what is to be carefully considered?

A

Whether the compound is diatomic