What mass of NaOH is in 250 mL of a 3.0M NaOH solution​

about 30g

Explanation:

Molarity = mol/L

*convert mL to L*

3M=xmol/.25

xmol = .75

*convert to g

.75 mol NaOH * 40g/mol = 30 g

Explanation:

Explanation: It's a 3.0 M solution so 1 litre of solution contains 3 moles of NaOH. 250 ml of solution therefore contains 0.25 x 3 = 0.75 moles of NaOH. The molar mass of NaOH is 39.9971 g/mol, so 250 ml of this solution contains 0.75 x 39.9971 = 29.99 g, or if you round it up 30.0 g.

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.