Please help me with these AP CHEM homework problems problems and show me the steps:

Mass per Volume Results for Titrations: Determine the mass per volume results requested in the following problems.

#23) A particular water supply is found to contain 0.000160 MAs, what is the concentration as milligrams As per liter of water?

#26) A sample if blood is analyzed for total calcium, the result (0.00236 Mcalcium) is very near the middle of the normal range for adults (8.5-10.5 mg/dL). Use unit conversions to determine the milligram per deciliter (mg/dL) concentration of calcium in the 0.00236Mcalcium blood sample?
1000 milligrams = 1grams
10 deciliter = 1 liter

For #23, what is an MA?

For #26, what is the nature of your trouble?

Also, for #23, you can't convert to mass without a molar mass somewhere.

To solve both of these problems, we need to convert between units of concentration. Here are the steps to solve each problem:

#23) To determine the concentration as milligrams As per liter of water:
Step 1: Write down the given concentration of 0.000160 MAs (moles of As per liter of water).
Step 2: Use the molar mass of As (arsenic) to convert from moles to grams. The molar mass of As is 74.9216 g/mol.
0.000160 mol As * 74.9216 g/mol = 0.011987 g As
Step 3: Use the conversion factor of 1 gram = 1000 milligrams to convert from grams to milligrams.
0.011987 g * 1000 mg/g = 11.987 mg
Step 4: Since the question asks for the concentration in milligrams As per liter of water, the final answer is:
11.987 mg/L

#26) To determine the milligram per deciliter (mg/dL) concentration of calcium in the 0.00236Mcalcium blood sample:
Step 1: Write down the given concentration of 0.00236 Mcalcium (moles of calcium per liter).
Step 2: Use the molar mass of calcium to convert from moles to grams. The molar mass of calcium is 40.08 g/mol.
0.00236 mol calcium * 40.08 g/mol = 0.0947264 g calcium
Step 3: Use the given conversion factor of 1 liter = 10 deciliters to convert from liters to deciliters.
1 L * 10 dL/L = 10 dL
Step 4: Use the conversion factor of 1 gram = 1000 milligrams to convert from grams to milligrams.
0.0947264 g * 1000 mg/g = 94.7264 mg
Step 5: Finally, divide the result by 10 to account for the conversion from milligrams per liter to milligrams per deciliter.
94.7264 mg / 10 dL = 9.47264 mg/dL

So, the concentration of calcium in the 0.00236Mcalcium blood sample is 9.47264 mg/dL.