To launch a rocket, liquid oxygen and liquid hydrogen are combined inside the rocket engine to react explosively. How do you think scientists take into account the law of conservation of mass when they calculate the amount of fuel needed for a rocket launch?

Explanation:

In this chemistry lab, students investigate how to build and launch a simple rocket that uses hydrogen and oxygen gases that will be mixed to propel the rocket (large bulb plastic pipette). Students will understand the principles of combustion reactions, kinetics, stoichiometry of reactions, activation energy, explosive mixtures, rocketry, and different types of chemical reactions. Students will explore and determine the proportions of hydrogen and oxygen mixture that will achieve the best launch results. Students will compare the balanced chemical reaction of hydrogen and oxygen with their lab results; students should discover that the optimal distance occurs when the mixture of hydrogen and oxygen is two to one hydrogen, oxygen mixture ratio and this can be determined theoretically from the balanced chemical reaction equation. Students will perform the lab, collect data, and discuss, compare, and contrast their lab findings with the balanced chemical reaction equation. Students will present their structured inquiry investigations using a power-point presentation. Other groups along with the teacher will assess each group by using a provided rubric. Group assessments will be the deciding assessment for the final lab score. A follow up activity could investigate how NASA scientists launch real rockets into space and propose a procedure to investigate and collect data on a launching a heavier object at the school football field.

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.

where's the diagram?