Answers
Activity (A) of an element is related to the number of atoms of that element N as follows:
A = k*N --------(1)
k = rate constant = 0.693/t1/2--------(2)
N = # moles of that element * Avogadro's number Na
For Sr: t1/2 = 28.8 yr
A(Sr) = 0.693/28.8 * N(Sr) = 0.0241 * N(Sr)
A(Sr) = 0.0241*(mass Sr/90)*Na= 0.000268 *mass Sr *Na ------------(3)
For Co : t1/2 = 5.26 yr
A(Co) = 0.693/5.26 *N(Co) = 0.1317 *N(Co)
A(Co) = 0.1317 * (1/60)*Na = 0.00219 * Na -------(4)
It is given that:
A(Sr) = A(Co)
0.000268 *mass Sr *Na = 0.00219 * Na
mass Sr = 0.00219/0.000268 = 8.17 g
Related Questions
Place whole number coefficients in the blanks to balance the chemical reaction. ____ KOH + ____ AlCl3 --> _____ Al(OH)3 + _____KCl
Which phase changes will result in an increase in energy of the substance
The following figure represents the formation of an ionic compound. Substances A and B are initially uncharged, but when mixed electrons are transferred. Using the figure, identify which substance will form the cation and which will form the anion. Provide a brief (one or two sentences) explanation for your response. (Hint: How does losing electrons affect atomic radii?)
One cubic meter of an ideal gas at 600 K and 1000 KPa expand to five times its initial volume as follows:(a) By a mechanically reversible, isothermal process [T 2 = 600K; P 2 = 200kPa; W= -1609 kJ](b) By a mechanically reversible, adiabatic process [T 2 =208.96K; P 2 = 67.65 kPa; W= -994.4 kJ] For each case calculate the final temperature, pressure and the work done by the gas. C p =21 Jmol- 1K-1.
True
False
Answers
Answer: False
Explanation: Alloys are harder and stronger because the different-sized atoms of the mixed metals make the atomic layers less regular, so they cannot slide as easily.
Answers
♫ - - - - - - - - - - - - - - - ~Hello There!~ - - - - - - - - - - - - - - - ♫
➷ 1) Enzyme A
[This is because a pH below 7 is acidic and the optimum pH is 1 for this enzyme]
2) Enzyme C
[pH 7 is neutral]
3) Enzyme D
[A pH above 7 is 'basic']
4) Enzyme B
[It is still below 7 but it is closer to neutral so it is just 'acidic']
✽
➶ Hope This Helps You!
➶ Good Luck (:
➶ Have A Great Day ^-^
↬ ʜᴀɴɴᴀʜ ♡
1st one is A
2nd one is C
3rd one is D
4th one is B
(Brainliest plz)
A FULL STEP EXPLANATION WILL BE APPRECIATED
Answers
The number of moles of iron needed to react with 16.0 moles of sulfur is 128.0 moles.
Calculation of number of moles of iron
Given equation, 8Fe + S8 = 8 FeS
Moles of sulfur = 16.0
To react 1 mole of sulfur, we need 8 moles of Fe
So, for 16.0 moles of sulfur we need
Thus, to react with 16.0 moles of Sulfur, 128.0 moles of Fe is needed.
Learn more about sulfur, here:
Answer:
To react with 16.0 moles of sulfur we need 128.0 moles of iron (Fe).
Explanation:
Step 1: Data given
Number of moles Sulfur = 16.0 moles
Step 2: The balanced equation
8 Fe + S8 → 8 FeS
Step 3: Calculate mole Fe
For 8 moles Fe we need 1 mol S8 to produce 8 moles FeS
For 16.0 moles of Sulfur we need 8*16.0 = 128.0 moles
To react with 16.0 moles of sulfur we need 128.0 moles of iron (Fe).
Answers
Answer:
4.88 Cals per degree celsius
Explanation:
We have taken heat of fusion of ice = 80 cals / g
We have taken speciic heat of water = 1 cal/g per degree celsius
In this experiment , let the heat capacity of calorimeter be X.
Heat gained by ice
heat gained in melting + heat gained in getting warmed
= mass x latent heat + mass x specific heat x rise in temperature
= 17.69 x 80 + 17.69 x 1 x ( 12.9 - 0 )
= 1643.4 Cals
Heat lost by water
= mass x specific heat x fall in temperature
98.67 x 1 x ( 28.77 - 12.9 )
= 1565.89 Cals
Heat lost by calorimeter
heat capacity x fall in temperature
X x ( 28.77 - 12.9 )
Heat gained = heat lost
1643.4 = 1565.89 +15.87X
X = 4.88 Cals per degree celsius
_ ML = 8,000,000 L
Answers
Answer:
To find the value of the blank in the equation "_ ML = 8,000,000 L," you can simply fill in the blank with a number:
"_ ML = 8,000,000 L" can be filled in as "8,000 ML = 8,000,000 L."
So, the answer is 8,000 ML.
Culled from AI
Answers
Answer:
Option 3.
Explanation:
Isomerism is a phenomenon where by two or more compounds have the same molecular formula but different structural patterns.
Geometric Isomerism is a type of Isomerism that occurs within a double bond i.e Geometric isomers have different arrangement within the double bond.
Considering the options given above,
The 1st option is exactly the same as the compound only, it is inverted.
The 2nd option is still the same as the compound, only it is laterally inverted.
The 3rd option satisfy geometric Isomerism as the arrangement differ from the compound in the double bond.
The 4th option is entirely a saturated compound in which geometric Isomerism is not possible.