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V= 50cm\(^{3}\) Mass= 5.05g Relative molecular mass of KN\(O_3\) = (39+14+(3*16)) = 101 Convert 50cm\(^{3}\) to dm\(^{3}\) which is 1000cm³ = 1dm\(^{3}\) 50cm³ = 50*1/1000 = 0.05dm\(^{3}\) Moles = mass/ molar mass = 5.05/101 =0.05mole Solubility= mole/volume Solubility=0.05mol/0.05dm\(^{3}\) Solubility=1.0mol/dm_\(^{3}\)

The reactivity series allows us to predict how metals react. A more reactive metal displaces a less reactive metal from a compound. Lead is more reactive metal than copper hence, copper is displaced from copper solution by lead.

. % of C in Ca(HCO3)2 Molar mass of Ca(HCO3)2 = 40+(1+12+(16*3))2 =40+(13+48)2 =40+122 =162 C/Ca(HCO3)2 x 100 =12 * 2/162 * 100 =14.8%

Hydrogen bond is an intermolecular force which arises when hydrogen is covalently linked to elements like nitrogen, oxygen and fluorine.

Nitrogen has three unpaired electrons and one lone pair of electrons; therefore, it can form three covalent bonds and one coordinate bond. E.g ammonium ion.

- Recognise the functional group in the compound. This will determine the suffix of the name - Find the longest continuous carbon chain that contains the functional group (it won't always be a straight chain) and count the number of carbon atoms in this chain. This number will determine the prefix (the beginning) of the compound's name - Number the carbons in the longest carbon chain (Important: If the molecule is not an alkane (i.e. has a functional group) you need to start numbering so that the functional group is on the carbon with the lowest possible number). Start with the carbon at the end closest to the functional group. - Look for any branched groups: Name them by counting the number of carbon atoms in the branched group and referring to Table 4.6, these groups will all end in -yl. Note the position of the group on the main carbon chain. If there is more than one of the same type of branched group then both numbers must be listed (e.g. 2,4 -) and one of the prefixes listed in Table 4.7 must be used. Important: If the molecule is an alkane the branched group must be on the carbon with the lowest possible number. The branched groups must be listed before the name of the main chain in alphabetical order (ignoring di/tri/tetra). If there are no branched groups this step can be ignored. - For the alkyl halides the halogen atom is treated in much the same way as branched groups: To name them take the name of the halogen atom (e.g. iodine) and replace the -ine with -o (e.g. iodo) Give the halogen atom a number to show its position on the carbon chain. If there is more than one halogen atom the numbers should be listed and a prefix should be used (e.g. 3,4-diiodo- or 1,2,2-trichloro-). See Table 4.7 for a list of the prefixes. The halogen atoms must be listed before the name of the main chain in alphabetical order (ignore di/tri/tetra). If there are no halogen atoms this step can be ignored. - Combine the elements of the name into a single word in the following order: branched groups/halogen atoms in alphabetical order (ignoring prefixes) prefix of main chain name ending according to the functional group and its position on the longest carbon chain.

As the nuclear charge increases, its attraction for the outermost electron increases and so more energy is required to remove the outermost electron. Hence, the ionization energy increases.

- Ionization behaviour; The atoms of non-metals usually have four to seven valence electrons. They have a great tendency to ionize by accepting electrons to form negative ions. - Reaction with acids; A metal which is more electro positive than hydrogen readily displaces the hydrogen ion, H+, from an acid.

- So any electron configuration in which the last electron (again, the valence electron) is in a higher energy orbital, this element is said to be in an excited state. - When a carbon atom becomes excited by absorbing energy, one of its 2s electrons is promoted into the 2p sublevel.

An amphoteric oxide is an oxide that can act as either an acid or base in a reaction to produce a salt and water.

Metals are effectively lots of positively charged ions with a cloud/sea of delocalised electrons. This means the electrons are free to move throughout the metal, and is also why metals can conduct electricity as the electrons can move. The more delocalised electrons a metal has, the stronger it will be held together.

Selenium is a chemical element with the symbol Se and atomic number 34. It is a non-metal

Electropositivity is known to increase down groups and decrease across periods in the modern periodic table (i.e., electropositivity decreases from left to right and it increases from up to down).

Q has slightly lower boiling point which when expose to air may evaporate rapidly.

Aluminium oxide is an amphoteric oxide. With sodium hydroxide solution, it produces water and sodium aluminate (NaAlO2). The other common examples of amphoteric oxides include SnO, ZnO, and PbO. Al2O3 is an amphoteric oxide.