A chemist uses hot hydrogen gas to convert chromium oxide to pure chromium how many grams of hydrogen are needed to convert 76 grams of chromium oxide Cr2O3+3H2 --> 2Cr + 3H2O

According to the passage, which of these is true about gray water systems? a) gray water systems use plants that require less water. eliminate b) gray water systems require the use of less fossil fuels. c) gray water systems reduce the amount of fresh water used. d) gray water systems reduce the amount water used by shower heads.