Some one can you guys help me:)

What is the ph of a solution with a 1.50 × 10−9 m hydroxide ion concentration?

Write the balanced equation for a reaction between aqueous nitric acid (hno3) and solid lithium metal (this is a single replacement reaction)

24. a sports ball is inflated to an internal pressure of 1.85 atm at room temperature (25 °c). if the ball is then played with outside where the temperature is 7.5 °c, what will be the new pressure of the ball? assume the ball does not change in volume nor does any air leak from the ball a) 0.555 atm b) 1.74 atm c) 1.85 atm d) 1.97 atm