(b). A metallic element M(2.94g) reacts completely with 0.0158mol gas X2 to form 4.04gMX. Identify M and X. (5 marks) (c). In titration, a few drops of phenolphthalein indicator was added into 50.00mL of HNO3 in a flask. Then, 15.00mL of 0.0491MNaOH was quickly added until the solution turns into deep pink (overshoot the endpoint). Instead of starting over, 25.00mL of HNO3, and the solution turns colourless. Then, it takes 4.13mL of the NaOH to reach the end point. (i). Determine the concentration of the HNO3 solution. 4 (ii). Calculate how many moles of NaOH were in excess after the first addition. (10 marks)