What is a device invented in 1889 that plays circular, flat records?

The overall chemical reaction for photosynthesis isshown below: 6co2 + 6h20 → c6h12o6 + 602what mass of glucose (c6h1206) can form from71.89 g co2? (molar mass of c6h1206 = 180.18g/mol; molar mass of co2 = 44.01 g/mol)71.89 g co2=g c6h1206

Given sno2 + 2h2 - sn + 2h20 tin oxide reacts with hydrogen to produce tin and water. how many moles of sno2 are needed to produce 500.0 grams of sn?

The content of manganese (mn) in steel was determined spectrophotometrically and with the use of the standard addition method. an unknown sample of mn from a digested steel sample gave an absorbance of 0.185 when analyzed spectrophotometrically. when 5.00 ml of solution containing 95.5 ppm mn was added to 50.0 ml of the unknown steel solution (digested sample), the absorbance was 0.248. calculate the concentration, in parts-per-million (ppm), of mn in the digested steel sample solution.