Give me answers! don’t send me any link, just give me the answers.
this question will give you 10 points

Answer and explanation:

1. To increases the accuracy of the measurement, the person should try to make sure the ruler is parallel to the object they are measuring. If they measure the object with the ruler not being parallel the measurement will end up larger then expected. To increase the precision the person must measure with the ruler in the same position each time.

2. A situation in which a set of measurements are precise but not accurate could be if a student measured an object at an incorrect angle many times, like the inaccurate measuring in the image above. All of the measurements would be inaccurate, but since they were all measured inaccuratly the same way, they will be precise.

3. An objects mass is defined as being the amount of matter in said object. An objects weight is defined as being the force exerted on an object by gravity. Although the man would weigh less on the Moon because there is less gravity, he still would not fit in his clothes because his mass has not changed.

first, consult an activity series chart to determine if al is more reactive than fe. it is, so it will replace the fe. now, one can continue with the problem.

next, make sure you have a correctly balanced equation.

3feo + 2al ==> 3fe + al2o3

now, determine which reactant (feo or al) is in limiting supply.

moles feo present = 125 g x 1 mole/71.8 g = 1.74 moles

moles al present = 25.0 g x 1 mole/26.98 g = 0.927 moles

since from the balanced equation, it take 3 mol feo for every 2 mol al, al will be limiting.

you can determine this simply by dividing moles of each by their coefficient in the balanced equation. for example: 1.74/3 = 0.58 and 0.927/2 = 0.464. al is less, so it is limiting.

finally, using the stoichiometry in the balanced eq. determine mass of fe that can be produced from 0.927 moles of al.

0.927 moles al x 3 moles fe/2 moles al x 55.8 g/mole = 77.6 g

a:

by the combination of an unlimited number of elements