From the periodic table you get the atomic masses of each element.
These are the values that I have in my periodic table (use those numbers of your periodic table if your teache gave you a specific one)
Na: 23 g/mol
O: 16 g/mol
H: 1 g/mol
C: 12 g/mol
Ca: 40 g/mol
S: 32 g/mol
Mg: 24 g/mol
P: 31 g/mol
Now I will do some examples and you do the others:
1) NaOH: 1 atom of Na * 23 g/mol + 1 atom of O * 16 g/mol + 1 atom of H * 1 g/mol
=> 1*23g/mol + 1*16g/mol + 1*1g/mol = 40 g/mol
2) H2O
=> 2 atoms of H * 1 g/mol + 1 atom of O * 16 g/mol = 2*1g/mol + 1*16g/mol = 18 g/mol
3) Glucose: C6H12O6
6*12 g/mol + 12 * 1g/mol + 6*16 g/mol = 72g/mol + 12g/mol + 96 g/mol = 180 g/mol
4) CaSO4:
1*40 g/mol + 1*32g/mol + 4*16g/mol = 136 g/mol
Now you only have to do the last one by your own.
Answer:
Explanation:
6.023 × 10²³ atoms of Ca are in 1 mol of Ca
Magma/Lava is mainly composed of silica, with some traces of oxygen. :D
I can't answer it if I can't see the image.
Answer is: molar mass of xylene 106,18 g/mol.
m(xylene) = 7,94 g.
m(cyclohexane) = 132,5 g.
T (solution) = - 4,9 °C.
Tf(cyclohexane) = 6,5 °C, frezing point.
Kf(cyclohexane) = 20,2 K·kg/mol; cryoscopic constant.
ΔT(solution) = 6,5°C - (-4,9°C) = 11,4°C = 11,4 K.
M(xylene) = Kf · m(xylene) ÷ m(cyclohexane) · ΔT(solution).
M(xylene) = 20,2 K·kg/mol · 7,94 g ÷ 0,1325 kg · 11,4 K.
M(xylene) = 106,18 g/mol.
