Answer:
Explanation:
Isotopes are atoms of elements that have the same atomic number but different mass number hence ISOTOPY. Radioactive Isotopes on the other hand are unstable as they either undergo Alpha decay, beta decay or gamma decay compared to stable isotopes.
Radioactive elements decay at varyinf rates as such the rate of radioactive decay is used in the characterization of radioactive element and mostly expressed in terms of the half life of the radioactive elements.
Half life is the time taken for half of the total atoms of an elements to decay into half of its initial sizes. for example, the half life of radium-226 is 1622 years, it implies that if we have 1000000 radium atoms at the beginning, then at the end of 1622years, 500000 would have disintegrated. These phenomenon can never be experienced by stable isotopes as such they can not be used in carbon dating techniques. reason why uranium-238 is mostly and commonly used in the earth crust to estimate the ages of rocks because it has a half life of 4.5 x 10^9 years.
And also, the radioactive isotopes of most common light element are short, they have very short half life (few days or weeks) and they decay rapidly to vanshing point, as such, they are not found in nature to any reasonable extent.
Answer:
Number of moles of Fe = 10 mol
Number of moles of CO₂ = 15 mol
Explanation:
Given data:
Number of moles of iron oxide = 5 mol
Number of moles of carbon monoxide = 25 mol
Number of moles of product = ?
Solution:
Fe₂O₃ + 3CO → 2Fe + 3CO₂
Now we will compare the moles of reactant with product.
Fe₂O₃ : Fe
1 : 2
5 : 2×5 = 10 mol
Fe₂O₃ : CO₂
1 : 3
5 : 3×5 = 15 mol
CO : Fe
3 : 2
25 : 2/3×25 = 16.7 mol
CO : CO₂
3 : 3
25 : 25
Less number of moles of Fe and CO₂ are formed by iron oxide thus it will act as limiting reactant while CO is inn excess.
Answer:
7.00
Explanation:
When the solutions are mixed, the HCl dissociates to form the ions H+ and Cl-. The ion H+ will react with the NH3 to form NH4+. The stoichiometry for this is 1 mol of HCl to 1 mol of H+ to 1 mol of Cl-, and 1 mol of H+ to 1 mol of NH3 to 1 mol of NH4+.
First, let's find the number of moles of each one of them, multiplying the concentration by the volume:
nH+ = 0.15 M * 25 mL = 3.75 mmol
nNH3 = 0.52 M * 25 mL = 13 mmol
So, all the H+ is consumed, and the neutralization is completed, thus pH will be the pH of the solvent (water), pH = 7.00.
Answer:
The new volume of a gas at 750 mmhg and with a volume of 2. 00 l when allowed to change its volume at constant temperature until the pressure is 600 mmhg is 2.5 Liters.
Explanation:
Boyle's law states that the pressure of a given amount of gas is inversely proportional to it's volume at constant temperature. It is written as;
P ∝ V
P V = K
P1 V1 = P2 V2
Parameters :
P1 = Initial pressure of the gas = 750 mmHg
V1 = Initial pressure of the gas = 2. 00 Liters
P2 = Final pressure of the gas = 600 mmHg
V2 = Fimal volume of the gas = ? Liters
Calculations :
V2 = P1 V1 ÷ P2
V2= 750 × 2. 00 ÷ 600
V2 = 1500 ÷ 600
V2 = 2.5 Liters.
Therefore, the new volume of the gas is 2. 5 Liters.
Answer:
1.41 moles H2O2(with sig figs)
Explanation:
okay so what is the molar mass of H2O2= (1.008 g/mol)2+(16.00g/mol)2= (2.016+ 32.00) g/ mol
= 34. 02 g/mol
48.0g H2O2* 1 mol H2O2/ 34.02 g H2O2= 1.41 mol H2O2
