Atomic Structure and Isotopes

Question 1

What is an isotope?

Answer 1

An atom with the same number of protons (of the same element) but a different number of neutrons and a different mass

Question 2

What is the formula of a sulfate?

Answer 2

SO₄

Question 3

What is the formula of a nitrate?

Answer 3

(NO₃)

Question 4

What is the formula of a hydroxide?

Answer 4

(OH)

Question 5

Give the definition of relative atomic mass

Answer 5

The weighted mean mass of an atom of an element relative to 1/12th of the mass of an atom of carbon 12

Question 6

Give the definition of the relative isotopic mass

Answer 6

The mass of an isotope relative to 1/12 of the mass of an atom of carbon 12

Question 7

What is avogadros constant?

Answer 7

6.02 x 10²³

Question 8

How do you calculate the numbers that will be in the empirical formula

Answer 8

1. You find the moles of each of the atoms in the element
2. Divide each of the moles by the smallest moles
3. That will give you the ratio
4. Use this to write the empirical formula

Question 9

The little numbers in the empirical formula of a compound must always be [blank]

fill in the blank

Answer 9

The little numbers in the empirical formula of a compound must aways be whole numbers

!!! so if you get a decimal number ending in .5 DOUBLE EVERYTHING, and if its a decimal that can easily be rounded ROUND IT NOWWWWW

Question 10

Which type of structure is written using empirical formula?

Answer 10

GIANT STRUCTURES (Covalent AND Ionic)

Question 11

Which type of structure is written using molecular formula?

Answer 11

Simple/small covalent bonds

Question 12

How do you calculate the molecular formula?

Answer 12

1. Calculate the empirical formula of the compound
2. Calculate the Mr of the compound using this empirical formula
3. Divide the given relative molecular molar mass by the Mr (molar mass) of the empirical formula
4. Multiply the quotient by the Mr of the empirical formula
5. Et voila! you have your molecular formular

Question 13

How do you use the empirical formula to calculate the molecuar formula?

Answer 13

1. You divide the given relative molecular Mr by the Mr of the compound which is found using the empirical formula
2. Then multiply each subscript in the empirical formula by this quotient to find the molecular formula

Question 14

What is Avogadro’s LAW

not constant but his LAW

Answer 14

In room temperature and pressure, one mole of gas occupies 24 dm³

Question 15

In what conditions does Avogadro’s LAW not work

Answer 15

When it is not room temperature and pressure

Question 16

What is the equation for Avogadro’s Law?

Answer 16

moles of GAS= volume/24dm³
or
volume= moles of GAS x 24dm³

or 24000cm³ bc that equals 24dm³

Question 17

What is the equation for ideal gas

Answer 17

pV=nRT

Question 18

What does p stand for in the ideal gas equation?

Answer 18

Pressure

Question 19

What are the units of pressure in the ideal gas equation?

Answer 19

Pa, Pascals

Question 20

How many Pascals in 1 Atmosphere?

Answer 20

101325 Pascals

Question 21

How many atmospheres in 101325 Pascals?

Answer 21

1 Atmosphere

Question 22

What does the V stand for in the ideal gas equation?

Answer 22

Volume

Question 23

What is the unit for volume in the ideal gas equation

Answer 23

1 metre³

Question 24

How many dm³ in 1m³?

Answer 24

1000 dm³

Question 25

**What** does the **n stand for** in the **ideal gas equation**?

Answer 25

**Moles**

Question 26

**What** does **R** stand for in the **ideal gas equation**?

Answer 26

**Gas constant**

Question 27

**What** is the **Gas constant** ## Footnote **a number**

Answer 27

**8.314**

Question 28

**What** does the **T stand for** in the **ideal gas equation**?

Answer 28

**Temperature**

Question 29

**What** are the **units** for **temperature** in the **ideal gas equation**?

Answer 29

**K, Kelvin**

Question 30

**How** many **Kelvin** in **0 degrees Celcius**?

Answer 30

**273 Kelvin**

Question 31

**How** do you **convert** from **degrees Celcius** to **Kelvin**?

Answer 31

**Add 273**

Question 32

**What** is the **symbol** for **ammonia**?

Answer 32

**NH₃**

Question 33

**What** is the **symbol** for **sulfuric acid**?

Answer 33

**H₂SO₄**

Question 34

**Give** the **definition** of a **salt**

Answer 34

When the **H⁺ ion** in an **acid** is **replaced** by a **metal ion**

Question 35

**How** do you **identify** what the **base is** in a **neutralisation reaction**?

Answer 35

It **accepts H⁺ ions**

Question 36

**What** is a **base**?

Answer 36

**Chemicals** that **neutralise acids** producing **salt** and **water**

Question 37

**What** does the **large dot** in a **hydrated salt formula show**?

Answer 37

It shows that the **water molecules** are **bound up** in the **ionic lattice**

Question 38

**How** do you **calculate** the **formula** of a **hydrated salt**?

Answer 38

1. **Work out** the **moles** of the **salt** and the **water** 2. **Divide both** of the **moles** by the **smallest one** 3. You then use this to show the **whole number ratio** ## Footnote if its .5, double everything, if its a roundable number, round itttt!

Question 39

**What** is the **definition** of **percentage uncertainty**?

Answer 39

The **uncertainty** in your **measurements expressed** as a **percentage** of the **results**

Question 40

**What** is the **equation** to calculate **percentage uncertainty**?

Answer 40

**(total uncertanty/result) x 100**

Question 41

**What** is the units for **moles** in the **m=cxv equation**?

Answer 41

**dm³** ## Footnote 1dm³³

Question 42

**What** are **units** for **concentration** in the **m=c x v equation**?

Answer 42

**M** or **moles/dm³**

Question 43

**How many mL** in **1cm³**

Answer 43

**1mL=1cm**

Question 44

**What** do you **calculate** when you asked to find the **volume** of a **subtance** at **room temperature** and **pressure**?

Answer 44

**Mole x 24dm³** ## Footnote or 24000cm³

Question 45

**Give** the **definition** of **empirial formula**

Answer 45

The **simplest whole number ratio** of **atoms/moles/elements**

Question 46

**Name four common cations** and **anions**

Answer 46

1.**Ammonium** 2.**Nitrate** 3.**Sulphate** 4.**Phostphate**

Question 47

**Give** the **equation** for **ammonium**

Answer 47

**NH₄⁺** | cation

Question 48

**Give** the **equation** for **nitrate**

Answer 48

**NO₃^-** | Anion

Question 49

**Give** the **equation** for **sulphate**

Answer 49

**SO₄^2-** | Anion

Question 50

**What** is an **alkali**?

Answer 50

A **soluble base** which **releases OH^-**

Question 51

**How** do you use the **total Mr** to find the **formula** of a **compound**

Answer 51

Using the **iterative method** 1. **Identify which** **atoms** are in the **compound** 2. **Subtract** the **first one's Mr** by the **total calculated Mr** 3. Then **divide** this answer by the **second atom's Mr** 4. If the number is a **whole number** then that is the number of the second atom there is in the compound and the first number is just what you multiplied the Mr of the first atom with. 5. It is iteratie because you just try this with ascending multiples of the 1st atoms Mr, until you get a whole number when you divide that answer by the 2nd number's Mr | lol its very long

Question 52

**Give** the **equation** for a **phosphate**

Answer 52

**PO₄³**

Question 53

**Give** an **example** of an **alkali**

Answer 53

**OH^-**

Question 54

**Give** an **example** of an **acid**

Answer 54

**H⁺**

Question 55

**Metal** + **acid** -> **[blank] + [blank]** | **fill in the blank**

Answer 55

Metal + acid -> **salt + hydrogen**