In a titration, 25.00 cm3 of 0.100 mol/dm3 sodium hydroxide solution is exactly neutralised by 20.00 cm3 of a dilute solution of hydrochloric acid. Calculate the concentration of the hydrochloric acid solution.

The unit is mol/dm3

Use the measurements in the table to determine which unidentified metal has the highest density. metal volume mass a 10.5 cm3 122 g b 14.2 cm3 132 g c 16.1 cm3 115 g d 12.7 cm3 126 g

At a certain temperature the rate of this reaction is first order in hi with a rate constant of : 0.0632s2hig=h2g+i2g suppose a vessel contains hi at a concentration of 1.28m . calculate how long it takes for the concentration of hi to decrease to 17.0% of its initial value. you may assume no other reaction is important. round your answer to 2 significant digits.

Describe the process that was used in this lab to create magnesium oxide, specifically identifying the type of chemical reaction. explain why the product had a higher mass than the reactant, and how this relates to conservation of matter.