Answer:
1034 yrs
Explanation:
The equation to use in this question is:
t = -2.303/k log (A/A₀) where
A= present number of disintegrations
A₀ = intial number of disintegrations
k = decay constant
The decay constant we will obtain it from the given hal-life:
k: 0.693/t₁/₂, t₁/₂ = half-life ⇒
k: 0.693 / 5730 y = 1.209 x 10⁻⁴ /y⁻¹
t = - 2.303 / 1.209 x 10⁻⁴ /y⁻¹ x log (13.1/15.3) = 1034 yrs
3.8mL of 0.42 phosphoric acid is required.
Reaction
2H3PO4 + 3CaCL3 → Ca3(PO)4 + 6HCl
moles CaCl2 =0.16 mol/L x0.010 L = 0.0016 mol
moles of H3Po4
= 0.0016mol of CaCl2 x 2 mole of H3PO4/3mole of CaCl2
= 0.00106 mol
V of H3PO4 = 0.0016/0.42 = 0.0038L = 3.8mL
V of H3PO4=3.8mL
To know more about calculation in milliliters refer to:-
brainly.com/question/23276655
#SPJ10
Answer:
Explanation:
Hello,
In this case, the first step is to compute the molar mass of carbon dioxide as shown below, considering it has one carbon atom and two oxygen atoms:
It is important to notice it is the mass in one mole of such compound. Afterwards, we need to use the Avogadro's number to compute the how many moles are in the given molecules of carbon dioxide as shown below:
Finally, the mass by using the molar mass:
Best regards.
Answer:
Hg Pb are in one, Li and B and O are in one, and NaCl are in one, As is alone
Explanation:
Periods are horizontal
Hope this helps!