Answer: a,b
Explanation: because a scientific theory is something that been thought of and tested multiple times.
Answer:
Rb+
Explanation:
Since they are telling us that the equivalence point was reached after 17.0 mL of 2.5 M HCl were added , we can calculate the number of moles of HCl which neutralized our unknown hydroxide.
Now all the choices for the metal cation are monovalent, therefore the general formula for our unknown is XOH and we know the reaction is 1 equivalent acid to 1 equivalent base. Thus we have the number of moles, n, of XOH and from the relation n = M/MW we can calculate the molecular weight of XOH.
Thus our calculations are:
V = 17.0 mL x 1 L / 1000 mL = 0.017 L
2.5 M HCl x 0.017 L = 2.5 mol/ L x 0.017 L = 0.0425 mol
0.0425 mol = 4.36 g/ MW XOH
MW of XOH = (atomic weight of X + 16 + 1)
so solving the above equation we get:
0.0425 = 4.36 / (X + 17 )
0.7225 +0.0425X = 4.36
0.0425X = 4.36 -0.7225 = 3.6375
X = 3.6375/0.0425 = 85.59
The unknown alkali is Rb which has an atomic weight of 85.47 g/mol
Answer:
0.234 moles
Explanation:
moles of Al2O3 = mass / molar mass
moles of Al2O3 = 23.87g / 102.0g/mol
moles of Al2O3 = 0.234 moles (to three significant figures)
Answer: Your best answer is A.
Explanation: 1.35 is a constant and thus is does not change. The equation can be simplified to-
“b = (0.29 x h)+ 1.35”
So, if your rider is say 60 inches tall, the equation would change to-
“b = (0.29 x 60)+ 1.35”
Then to-
“b = (17.4) + 1.35” or “b = 17.4 + 1.35”
And therefore the size of the BMX bike frame in inches would be-
“b = 18.75”
Hope this helped :)