Suppose you are asked to verify experimentally the electrode reactions shown in Example 18.8. In addition to the apparatus and the solution, you are also given two pieces of litmus paper, one blue and the other red. Describe what steps you would take in this experiment.

Module2 How can we represent numbers in a computer Numbers are kept in computer hardware as a series of high and low electronic signals, By encoding the signal we obtain values are above or below some threshold of pulses, we represents them as 1 3.3V2.8V (T), or a 0 (F) 0.5V0V. Strings of 1’s and 0’s can be interpreted as a number. all information are composed of binary digits or bits Also called binary bit. computer use on and off signals, so a decimal digit was simply represented by several binary digits. Decimal proved so inefficient. Conversion Formula • Given an nbit number x x 2 n1 x 2n2 x 2 x 2 0 n1 n2 1 0 Ex: 0000 0000 0000 0000 0000 0000 0000 1011 2 = 0 + … + 1×2 + 0×2 +1×2 +1×2 0 = 0 + … + 8 + 0 + 2 + 1 = 110 Placing these binary numbers side by side forms the instruction. Representing Instructions in the Computer you can see from counting the number of bits, this MIPS instruction takes exactly 32 bits—the same size as a data word. it from assembly language, we call the numeric version of instructions machine language and a sequence of such instructions machine code. Since almost all computer data sizes are multiples of 4, hexadecimal (base 16) numbers are popular. Since base 16 is a power of 2, we can trivially convert by replacing each group of four binary digits by a single hexadecimal digit, and vice versa Conversion Formula