Answer:
C
Explanation:
This experiment by Rutherford involved the firing of alpha particles at gold foils. It is also. called the gold foil experiment.
He fired these alpha particles at different points. He noticed that at some points, there were deflections, while at some other points, there were no deflections. It is necessary to state that these alpha particles are positively charged. For there to be a deflection, there must have been a kind of repulsion between the gold foil and the alpha particles.
From the basic physics of like repels like, he knew for sure that there must be dense positive core in the atom that is causing the deflection of the alpha particles. This enabled him to come up with the theory that the atom contained a small dense positive core called the nucleus
A 0.00143 M concentration of MnO4^- is not a reasonable solution .
<h3>Number of moles of carbonate</h3>
The ions left in solution are Na^+ and NO3^-
Number of moles of calcium nitrate = 100/1000 L × 1 = 0.1 moles
Since;
1 mole of sodium carbonate reacts with 1 mole of calcium nitrate then 0.1 moles of sodium carbonate were used.
<h3>Conductivity of filtrate</h3>
The claim of the student that the concentration of sodium carbonate is too low is wrong because the value was calculated from concentration and volume of calcium nitrate and not using the precipitate. If the filtrate is tested for conductivity, it will be found to conduct electricity because it contains sodium and NO3 ions.
2) In the reaction as shown, the MnO4^- ion was reduced.
The initial volume is 3.4 mL while the final volume is 29.6 mL.
Number of moles of MnO4^- ion = (29.6 mL - 3.4 mL)/1000 × 0.0235 M = 0.0006157 moles
<h3>The calculations are performed as follows</h3>
- If 2 moles of MnO4^- reacted with 5 moles of acid
0.0006157 moles of MnO4^- reacted with 0.0006157 moles × 5 moles/ 2 moles
= 0.0015 moles
- In this case, number of moles of acid = 0.139 g/90 g/mol = 0.0015 moles
Number of moles of MnO4^- = 0.00143 M × (29.6 mL - 3.4 mL)/1000
= 0.000037 moles
- If 2 moles of MnO4^- reacts with 5 moles of acid
0.000037 moles of MnO4^- reacts with 0.000037 moles × 5 moles/ 2 moles
= 0.000093 moles
- Hence, this is not a reasonable amount of solution.
Learn more about MnO4^- : brainly.com/question/10887629
Answer:
6.096799125kg
Explanation:
According to the question, three different samples weighed using different types of balance had masses: 0.6160959 kg, 3.225 mg, and 5480.7 g.
Based on observation, the mass units in the three measurements are different but must be uniform in order to find the total mass. Hence, we need to convert to the standard unit (S.I unit of mass), which is kilograms (kg)
Since 1kg equals 1,000,000mg
Hence, 3.225mg will be 3.225/1000000
= 0.000003225kg
Also, 1kg equals 1000g
Hence, 5480.7g will be 5480.7/1000
= 5.4087kg
Hence, the total mass of the three samples (now in the same unit) are:
5.4807kg + 0.000003225kg + 0.6160959 kg
= 6.096799125kg
Answer:
After 1326s, the concentration of pyruvic acid fall to 1/64 of its initial concentration.
Explanation:
The first order kinetics reaction is:
ln [A] = ln [A]₀ - kt
<em>Where [A] is concentration after t time, [A]₀ is intial concentration and k is reaction constant.</em>
To convert half-life to k you must use:
t(1/2) = ln 2 / K
221s = ln 2 / K
K = ln 2 / 221s
<h3>K = 3.1364x10⁻³s⁻¹</h3>
If [A] = 1/64, [A]₀ = 1:
ln [A] = ln [A]₀ - kt
ln (1/64) = ln 1 - 3.1364x10⁻³t
4.1588 = 3.1364x10⁻³s⁻¹t
1326s = t
<h3>After 1326s, the concentration of pyruvic acid fall to 1/64 of its initial concentration.</h3>
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I'll go with B, have a good day
