<< Chapter < Page Chapter >> Page >

K 2 SO 4 (s) 2 K + (aq) + SO 4 2 - (aq)

Remember that molecular substances (e.g. covalent compounds) may also dissolve, but most will not form ions. One example is sugar.

C 6 H 12 O 6 (s) C 6 H 12 O 6 (aq)

There are exceptions to this and some molecular substances will form ions when they dissolve. Hydrogen chloride for example can ionise to form hydrogen and chloride ions.

HCl(g) H + (aq) + Cl - (aq)

Interesting fact

The ability of ionic compounds to dissolve in water is extremely important in the human body! The body is made up of cells , each of which is surrounded by a membrane . Dissolved ions are found inside and outside of body cells in different concentrations. Some of these ions are positive (e.g. Mg 2 + ) and some are negative (e.g. Cl - ). If there is a difference in the charge that is inside and outside the cell, then there is a potential difference across the cell membrane. This is called the membrane potential of the cell. The membrane potential acts like a battery and affects the movement of all charged substances across the membrane. Membrane potentials play a role in muscle functioning, digestion, excretion and in maintaining blood pH to name just a few. The movement of ions across the membrane can also be converted into an electric signal that can be transferred along neurons (nerve cells), which control body processes. If ionic substances were not able to dissociate in water, then none of these processes would be possible! It is also important to realise that our bodies can lose ions such as Na + , K + , Ca 2 + , Mg 2 + , and Cl - , for example when we sweat during exercise. Sports drinks such as Lucozade and Powerade are designed to replace these lost ions so that the body's normal functioning is not affected.

Write a balanced equation to show how silver nitrate ( AgNO 3 ) dissociates in water.

  1. The cation is: Ag + and the anion is: NO 3 -
  2. Since we know both the anion and the cation that silver nitrate dissociates into we can write the following equation:
    AgNO 3 (s) Ag + (aq) + NO 3 - (aq)

Ions in solution

  1. For each of the following, say whether the substance is ionic or molecular.
    1. potassium nitrate ( KNO 3 )
    2. ethanol ( C 2 H 5 OH )
    3. sucrose (a type of sugar) ( C 12 H 22 O 11 )
    4. sodium bromide ( NaBr )
  2. Write a balanced equation to show how each of the following ionic compounds dissociate in water.
    1. sodium sulphate ( Na 2 SO 4 )
    2. potassium bromide ( KBr )
    3. potassium permanganate ( KMnO 4 )
    4. sodium phosphate ( Na 3 PO 4 )

Ions and water hardness

This section is not examinable and is included as an example of ions in aqueous solution.

Water hardness
Water hardness is a measure of the mineral content of water. Minerals are substances such as calcite, quartz and mica that occur naturally as a result of geological processes.

Hard water is water that has a high mineral content. Water that has a low mineral content is known as soft water . If water has a high mineral content, it usually contains high levels of metal ions, mainly calcium ( Ca ) and magnesium ( Mg ). The calcium enters the water from either CaCO 3 (limestone or chalk) or from mineral deposits of CaSO 4 . The main source of magnesium is a sedimentary rock called dolomite, CaMg(CO 3 ) 2 . Hard water may also contain other metals as well as bicarbonates and sulphates.

Questions & Answers

the art of managing the production, distribution and consumption.
Satangthem Reply
what is economics
Khawar Reply
okk
damfash
marginal utility is the additional satisfaction one derives from consuming additional unit of a good or service.
Fred
It's the allocation of scarce resources.
Fred
marginal utility please?
Dishan
marginal utility is the additional satisfaction one derives from consuming additional unit of a good or service.
Fred
I know the definition, but I don't understand its meaning.
Dishan
what is the must definition of economic please?
Nurudeen
demand lfs
Alpha
Economics is derived from the word Oikonomia which means management of household things. Thus, Economics is a study of household things with the constrains of allocating scare resources.
Dishan
what is Open Market Operation
Adu Reply
dominating middlemen men activities circumstances
Christy Reply
what Equilibrium price
Adji Reply
what is gap
mirwais
who is good with the indifference curve
Dexter
What is diseconomic
Alixe Reply
what are the types of goods
WARIDI
how can price determination be the central problem of micro economics
simon Reply
marginal cost formula
Nandu Reply
you should differentiate the total cost function in order to get marginal cost function then you can get marginal cost from it
boniphace
What about total cost
Foday
ok
Foday
how can price determination be the central problem if micro economics
simon
formula of cross elasticity of demand
Theresia Reply
what is ceteris paribus
Priyanka Reply
what is ceteris parabus
Priyanka
Ceteris paribus - Literally, "other things being equal"; usually used in economics to indicate that all variables except the ones specified are assumed not to change.
Abdullah
What is broker
scor
land is natural resources that is made by nature
scor
What is broker
scor
what is land
kafui
What is broker
scor
land is natural resources that is made by nature
scor
whats poppina nigga turn it up for a minute get it
amarsyaheed Reply
what is this?
Philo
am from nigeria@ pilo
Frank
am from nigeria@ pilo
Frank
so
owusu
what is production possibility frontier
owusu
it's a summary of opportunity cost depicted on a curve.
okhiria
please help me solve this question with the aid of appropriate diagrams explain how each of the following changes will affect the market price and quantity of bread 1. A
Manuela Reply
please l need past question about economics
Prosper Reply
ok let me know some of the questions please.
Effah
ok am not wit some if den nw buh by tommorow I shall get Dem
adepojurafiu
Hi guys can I get Adam Smith's WEALTH OF NATIONS fo sale?
Ukpen
hello I'm Babaisa alhaji Mustapha. I'm studying Economics in the university of Maiduguri
Babaisa
okay
Humaira
my name is faisal Yahaya. i studied economics at Kaduna state university before proceeding to West African union university benin republic for masters
Faisal
Hi guys..I am from Bangladesh..
Mannan
Wat d meaning of management
igwe Reply
disaster management cycle
Gogul Reply
cooperate social responsibility
igwe
Fedric Wilson Taylor also define management as the act of knowing what to do and seeing that it is done in the best and cheapest way
OLANIYI
What makes metals better to use as wires than non-metals? (please link to bonding type)??? HELP
Yash Reply

Get the best Algebra and trigonometry course in your pocket!





Source:  OpenStax, Chemistry grade 10 [caps]. OpenStax CNX. Jun 13, 2011 Download for free at http://cnx.org/content/col11303/1.4
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Chemistry grade 10 [caps]' conversation and receive update notifications?

Ask