Answer=B and D
Both are types of potential energy that involve stored energy.
Answer:
![d=0.417\ g/cm^3](https://tex.z-dn.net/?f=d%3D0.417%5C%20g%2Fcm%5E3)
Explanation:
Given that,
Mass, m = 10 g
Volume, V = 24 cm³
We need to find the density of the substance. We know that, the density of a substance is given by :
Density = mass/volume
So,
![d=\dfrac{10\ g}{24\ cm^2}\\\\d=0.417\ g/cm^3](https://tex.z-dn.net/?f=d%3D%5Cdfrac%7B10%5C%20g%7D%7B24%5C%20cm%5E2%7D%5C%5C%5C%5Cd%3D0.417%5C%20g%2Fcm%5E3)
So, the density of the substance is
.
1 moles -------- 6.02x10²³ atoms
?? moles ----- 7.4x10²¹ atoms
moles = 7.4x10²¹ / 6.02x10²³
= 0.01229 moles
hope this helps!
<u>Answer:</u> The half life of the reaction is 593.8 seconds
<u>Explanation:</u>
We are given:
Rate constant = ![0.0016mol/L.s](https://tex.z-dn.net/?f=0.0016mol%2FL.s)
The formula for determining the unit of 'k' is:
![\text{Unit}=\frac{(Concentration)^{1-n}}{Time}](https://tex.z-dn.net/?f=%5Ctext%7BUnit%7D%3D%5Cfrac%7B%28Concentration%29%5E%7B1-n%7D%7D%7BTime%7D)
where, n = order of reaction
The unit of concentration is, M or mole/L
The unit of time is, second or 's'
Evaluating the value of 'n' from above equation:
![mol.L^{-1}s^{-1}=\frac{(mol/L)^{1-n}}{s}\\\\n=0](https://tex.z-dn.net/?f=mol.L%5E%7B-1%7Ds%5E%7B-1%7D%3D%5Cfrac%7B%28mol%2FL%29%5E%7B1-n%7D%7D%7Bs%7D%5C%5C%5C%5Cn%3D0)
The reaction is zero order reaction.
The equation used to calculate half life for zero order kinetics:
![t_{1/2}=\frac{[A_o]}{2k}](https://tex.z-dn.net/?f=t_%7B1%2F2%7D%3D%5Cfrac%7B%5BA_o%5D%7D%7B2k%7D)
where,
k = Rate constant = ![0.0016mol/L.s](https://tex.z-dn.net/?f=0.0016mol%2FL.s)
= initial concentration = 1.90 mol/L
Putting values in above equation, we get:
![t_{1/2}=\frac{1.90mol/L}{2\times 0.0016mol/L.s}=593.8s](https://tex.z-dn.net/?f=t_%7B1%2F2%7D%3D%5Cfrac%7B1.90mol%2FL%7D%7B2%5Ctimes%200.0016mol%2FL.s%7D%3D593.8s)
Hence, the half life of the reaction is 593.8 seconds
Answer:
• A candle is burned
• Your silver teapot turns black
• Two clear colorless salt solutions are mixed and a bright orange precipitate forms.
Explanation:
A chemical change results from a chemical reaction of the species involved. Examples of chemical changes are burning, cooking, rusting etc.
Physical change when matter changes forms but not chemical identity. Examples of physical changes are boiling, melting, freezing, evaporation etc.