What is the mass of solution of sodium hydroxide whose mass concentration 10% and it contains 1 mole of solute? [Na = 40 , O=16 , H=1]

1) which of the following is the best example of a physical change? a) sugar dissolving in tea b) firefly glowing 2) in the combustion of ethane, what is/are the reactants? c2h6 + o2 ==> co2 + h2o a) c2h6 and o2 b) co2 and c2h6