If \( T = 2\pi \sqrt{\frac{L}{g}} \), \( g \) is a constant and the relative error in \( T \) is \( k \) times to the percentage error in \( L \), then \( \frac{1}{k} = \) ?
A hydrocarbon containing C and H has 92.3% C. When 39 g of hydrocarbon was completely burnt in O2, x moles of water and y moles of CO2 were formed. x moles of water is sufficient to liberate 0.75 moles of H2 with Na metal. What is the weight (in g) of oxygen consumed?