Answer:
B
Explanation:
living things are not required to move
Answer:
a. 6.57 cm
b. 8.17 cm
c. 0.80
Explanation:
a. The compound moved from where it was first placed, to a spot 7.57 cm from the bottom of the paper, in other words:
- 7.57 cm - 1.00 cm = 6.57 cm
b. A similar method is made for the solvent:
- 9.17 cm - 1.00 cm = 8.17 cm
c. The Rf of the factor is equal to the <u>distance that the compound moved divided by the distance the solvent moved</u>:
There are several reasons behind why they must keep accurate notes.
There may be a mistake or an anomaly that occurs during the process, and something completely different than the desired compound may be created and the process may need to be repeated.
The investigation may be successful and may need to be repeated.
The investigator may need to prove that the project was done by him and the notes may help him to do so. (hence why they must be dated and signed.)
The investigator may need them to protect him from legal action.
The pharmaceutical company may need proof that the possible medicine is safe and effective, and that it works as it should.
The reaction for the formation of MgO(s):
2 Mg (s) + O2(g) -à
2MgO(s) ΔH = -601.24
kJ/mol
<span>The enthalpy
information is taken from: http://webbook.nist.gov/cgi/inchi?ID=C1309484&Mask=2</span>
From the equation and with an enthalpy change of -231 kJ:
-231 kJ * 2 mol Mg * (1/-601.24 kJ/mol) = 0.76841 mol Mg
Then, with the molar mass of MgO = 40.3,
0.76841 mol Mg *(2 mol MgO/2 mol Mg)* 40.3 g/mol MgO = <span>30.967 g MgO</span>
Answer:
physical change
Explanation:
it it was just heated up and change into a different form