In a DEPT-135 spectrum, which labeled carbons in the molecules below would show positive and which would show negative peaks? a) b) CHACH а CH3 CH3 CH3 CH3 Positive peaks: Positive peaks: Negative peaks: Negative peaks:

Foreattt part of iTIS qtestfoni; tonsider FOHOWIHg Btetat: You need to make a stock solution of Ca( C2H3O2 )2 with a concentration of 6.50 M. You have a 850.0 mL volumetric flask available to make this stock solution in. You are then tasked with using this stock solution to prepare a sample for use in an experiment. The experimental sample should have a final volume of 15.0 mL and a concentration of 0.350 M Ca(C2H3O2)2. a) What is the molar mass of Ca(C2H3O2)2? b) How many moles of the solute would be needed to create the stock solution using the volumetric flask available? c) How many grams of the solute should be added to the volumetric flask to create the stock solution? d) What volume, in mL, of the stock solution should be used to prepare the experimental solution through dilution? US 目 M

Twenty tablets (labelled 300 mg aspirin per tablet) had a total mass of 6.9117 g. The tablets were powdered and 0.5423 g of powder was added to 30.0 mL 0.494 M sodium hydroxide solution and the mixture boiled gently for 10 minutes. The excess alkali in the cooled solution was titrated with 0.475 M hydrochloric acid solution and 20.25 mL required for neutralization. Given that aspirin (C9H8O4) and NaOH react in a 1:2 ratio calculate the percentage of aspirin as compared to the labelled claim. Aspirin Mr(C9H8O4) = 180.2

Masses :  Ca = 40.08 g   S= 32.07 g  O= 16.00 g  A 35.0 mL sample of CaSO4 was evaporated to dryness, leaving 0.967 g of residue. What was the molarity of the original solution?   step by step please