Answer: determines the age of sample Carbon-14 is used in radiocarbon dating and radiolabeling. Medically important, a radioactive isotope is carbon-14, which is used in a breath test to determine the ulcer-causing bacteria Heliobacter pylori
The radiocarbon age of a certain sample of unknown age can be determined by measuring its carbon 14 content and comparing the result to the carbon-14 activity in modern and background samples.
Answer:
850g/min
Explanation:
The reaction expression is given as:
P₄ + 5O₂ → P₄O₁₀
Given that:
Number of moles of product = 1.5moles
Time = 30s = 0.5min
Unknown:
The rate of the reaction = ?
Solution:
Convert the moles given to mass of the product.
So;
Mass of product = number of moles x molar mass
Molar mass of P₄O₁₀ = 4(31) + 10(16) = 284g/mol
Mass of product = 1.5moles x 284g/mol = 426g
So;
Reaction rate = 
= 
= 850g/min
Answer:
1) mass ZnO = 55.155 g
2) V SO2(g) = 18.289 L
Explanation:
1) Zn + H2O → ZnO + H2
∴ mass Zn = 41.6 g
∴ mm Zn = 65.38 g/mol
⇒ mol Zn = (41.6 g)(mol/61.38 g) = 0.678 mol Zn
⇒ mol ZnO = (0.678 mol Zn)(mol ZnO/mol Zn) = 0.678 mol ZnO
∴ mm ZnO = 81.38 g/mol
⇒ mass ZnO = (0.678 mol ZnO)(81.38 g/mol) = 55.155 g ZnO
2) S(s) + O2(g) → SO2(g)
∴ mass S(s) = 24 g
∴ T = 25°C ≅ 298 K
∴ P = 1 atm
∴ mm S(s) = 32.065 g/mol
⇒ mol S(s) = (24 g)(mol/32.065 g) = 0.7485 mol S(s)
⇒ mol SO2(g) = (0.7485 mol S(s))(mol SO2(g)/mol S(s)) = 0.7485 mol SO2(g)
ideal gas:
⇒ V SO2(g) = ((0.082 atm.L/K.mol)(298 K)(0.7485 mol))/(1 atm)
⇒ V SO2(g) = 18.289 L SO2(g)
Patent - Not sure if this is much of a Chem question dou.
Answer:
pH = 12.544
Explanation:
0.0350M 0.0350M 0.0350M.........equilibrium
∴ pOH = - log [OH-]
∴ pH + pOH = 14
⇒ [OH-] = 0.0350 M
⇒ pOH = - Log (0.0350)
⇒ pOH = 1.456
⇒ pH = 14 - 1.456
⇒ pH = 12.544
