How would you prepare a1L. solution of 3M MgO? A Dissolve 3 moles of MgO in 1 L of water. B Dissolve 3 grams of MgO in 1 L of water. C Place 120 g of MgO in a 1000mL volumetric flask and add 1 L of water to the beaker D Place 120 g of MgO in a 1000 mL volumetric flask and add enough water to reach the 1 L mark.

## Step 1: Determine the molar mass of MgO### The molar mass of MgO (Magnesium Oxide) is calculated by adding the atomic mass of Magnesium (Mg) and Oxygen (O). Mg = and O = . Therefore, the molar mass of MgO is .## Step 2: Calculate the required amount of MgO for a 3M solution### To make a 3M solution, dissolve 3 moles of MgO in 1 liter of water. The mass required is .## Step 3: Identify the correct preparation method### For a 1L solution, place 120 grams of MgO in a 1000 mL volumetric flask and add enough water to reach the 1L mark to get the correct concentration.