Which of the following show evidence that a chemical reaction has taken place: 1. Two liquids are combined and a gas is released. T or F
2. A substance is added to water and it dissolves. T or F
3. Two liquids are combined a solid precipitate forms. T or F
4. A new substance is formed. T or F
5. A SINGLE reactant changes from a solid to a liquid. T or F

anybody that dose not understand they are separate answers meaning question 1 then question 2 and etc.

Since the gas in your graduated cylinder is a mixture of butane and water vapor, you must determine the partial pressure of the butane, pbutane, alone. to do this, consult a reference and record the partial pressure of the water vapor, pwater, at the temperature you recorded. use the following formula to compute the partial pressure of the butane. pbutane = atmosphere - pwater use the following combined gas law formula and compute the volume that the butane sample will occupy at stp. (hint: convert both temperatures to kelvin.) pbutane x voriginal = pstandard x vfinal troom tstandard use the following ratio and proportion formula to determine the mass of butane needed to occupy a volume of 22.4 l at stp. grams of butane you used “x” grams of butane ml of butane corrected to stp = 22,400 ml compute the theoretical molar mass of butane based on its formula and the atomic masses on the periodic table. compare your experimental results from #3 to the theoretical value of #4, computing a percent error of your findings using this formula: % error = measured value - accepted value x 100 accepted value use the following ratio and proportion formula to determine the mass of butane needed to occupy a volume of 22.4 l at stp. need asap

Mercury turns to a vapor at 629.88 k. how much heat is lost when 75.0 g of mercury vapor at 650 k condenses to a liquid at 297 k?

Which of the following describes qualitative data? a) recording the temperature of a solid as it is warmed. b) noting the color of a solution as it is heated. c) measuring the volume of an object by water displacement. d) taking the mass of an object using a balance.