Calculate the volume of H2(g) at 273 K and 2.00 atm that will be formed when 275 mL of 0.725 M HCl solution reacts with excess Mg to give hydrogen gas and aqueous magnesium chloride

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)

Lab reagent, hypothesis test.a reference solution used as a lab reagent is purported to have a concentration of 5 mg/dl. six samples are taken from this solution and the following concentrations are recorded: (5.32, 4.88, 5.10, 4.73, 5.15, 4.75) mg/dl.these six measurements are assumed to be an srs of all possible measurements from solution.they are also assumed to have a standard deviation of 0.2, a normal distributin, and a mean concentration equal to the true concentration of the solution.carry out a significance test to determine whether these six measurements provide reliable evidence that the true concentration of the solution is actually not 5 mg/dl.

Maleic acid is a carbon-hydrogen-oxygen compound used in dyeing and finishing fabrics and as a preservative of oils and fats.* in a combustion analysis, a 1.054-g sample of maleic acid yields 1.599 g of co_2 and 0.327 g of h2o.* when 0.609 g of maleic acid is dissolved in 25.00 g of glacial acetic acid, the freezing point drops by 0.82 c. maleic acid does not ionize in glacial acetic acid, which has a freezing-point depression constant of k_{\rm f}=3.90~^\circ {\rm c}/m.* in a titration experiment, a 0.4250- g sample of maleic acid is dissolved in water and requires 34.03 ml of 0.2152 m koh for its complete neutralization.* the ph of 0.215 g of maleic acid in 50.00 ml of aqueous solution is found to be 1.80.part adetermine the empirical formula for maleic acid. enter the atoms in order ofc, h, and o.part bdetermine the molecular formula for maleic acid. enter the atoms in order of c,h, and o.express your answer as a chemical formula.part cbased on the titration data, how many ionizable h atoms are in each molecule of maleic acid, c4h4o4? express your answer as an integer.i got the part a and b which is cho and c4h4o4 respectively, can anyone me for part c? the below is what i have so far from other qa'sfinding the empirical formula for maleic acid, needs this info"a combustion analysis a 1.054-g sample of maleic acid yields 1.599g of and 0.327g of ".the rest of your data is used to find molar mass, molecular formula, equivalent mass, # of h+ ions / molecule & katypically this should be: a 1.054-g sample of maleic acid yields 1.599g of co2 and 0.327g of h2osofind mass using molar masses1.599g of co2 @ (12.01 g carbon) / (44.01 g co2) = 0.436 grams of carbon0.327g of h2o @ (2.016 g hydrogen) / (18.01 g/mol h2o) = 0.037 grams of hydrogen1.054-g sample - 0.436 grams of carbon - 0.037 grams of hydrogen = 0.581 grams of oxygennow use molar masses to find moles0.436 grams of carbon @ 12.01 g/mol = 0.0363 mol c0.037 grams of hydrogen @ 1.008 g/mol = 0.0367 mol h0.581 grams of oxygen @ 16.00 g/mol = 0.0363 mol oyour empirical formula ischo and molecular is c4h4o4