A0.4569 g sample of pewter, containing tin, lead, copper, and zinc, was dissolved in acid. tin was precipitated as sno2·4h2o and removed by filtration. the resulting filtrate and washings were diluted to a total volume of 250.0 ml. a 20.00 ml aliquot of this solution was buffered, and titration of the lead, copper, and zinc in solution required 34.02 ml of 0.001513 m edta. thiosulfate was used to mask the copper in a second 25.00 ml aliquot. titration of the lead and zinc in this aliquot required 34.42 ml of the edta solution. finally, cyanide was used to mask the copper and the zinc in a third 30.00 ml aliquot. titration of the lead in this aliquot required 25.92 ml of the edta solution. determine the percent composition by mass of each metal in the pewter sample.

Quickly! brainliest if two people answer! 1. the blood has red blood cells, white blood cells and platelets. red blood cells carry oxygen to other cells in the body. cells need oxygen to live. white blood cells destroy certain germs. they protect our bodies from disease. which question is answered in this paragraph? (a) what is the role of blood vessels? (b) what type of cells are attached to bones? (c) what type of blood cell to clot your blood? (d) what are the different types of blood cells? 2. which sentence from the section "stem cells" best explains the role of stem cells? (a) when one kind of cell stops working, stem cells can . (b) they can turn into that cell and take its place. (c) scientists are studying new ways to use stem cells. (d) these cells can people heal faster. 3. read the selection from the section "nerve cells." nerve cells send messages to the rest of our bodies. these messages move between the brain, spinal cord and various organs. nerve cells are also called neurons. fill in the blank. a "neuron" is a (a) cell that moves information from the brain to other parts of the body (b) stem cell that has both an axon and a dendrite (c) cell that controls the fingers of a body (d) cell that makes up the spinal cord 4. some muscles in our body move without us telling them to. these are called involuntary muscles. some examples are the cardiac muscle cells inside the heart. these cells the heart relax and fill with blood. what is the best definition of "involuntary" based on the context clues? (a) something that happens on its own (b) trying hard to do something (c) something moving back and forth (d) easily moved

How heavy is thanos? a) 3000 lbs b) all of it c) the price of tea in china d) heavy enough

The molality of calcium chloride (cacl2) in an aqueous solution is 2.46 m. what is mole fraction of the solute?