-Good experimental design plans how to record data so the data can be published. -Good experimental design involves only one trial in an experiment. -Good experimental design includes logging every step and data point of the experiment.
A change from physical change into chemical change not sure hope this helps
Mass of MnO2 = 25 g
The reaction would be 3MnO2 + 4Al --> 3Mn(s) + 2Al2O3
Molar mass of Al = 26.982 g/mol
Molar mass of MnO2 = 54.938 + 2(15.999) = 86.936 g/mol
Calculating the moles = 25 / 86.936 = 0.2876 mol.
Mole ratio MnO2 and Al considering the equation = 3 mol of MnO : 4 mol of Al
Calculating the moles of Al = 0.2876 mol MnO2 x (4 mol of Al / 3 mol of MnO)
Number of moles of Al = 0.3834
Getting the mass in grams as asked = 0.3834 mol x 26.982 g/mol = 10.34 grams.
Answer:
irreversible changes
Explanation:
Most chemical changes are permanent and cannot be reversed. That is because a chemical change involves changing the molecular composition which can't be reversed. A common example of a chemical change would be burning wood. The wood burning into ash is changing the molecular composition of the wood transforming it to ash. Now can ash be changed back into wood? No, it is a "irreversible change."
Hope this helps.