Answer:
Cell Wall
Explanation:
In plant cells, the cell wall is rigid the outer structure that protects the plant cell.
Answer:
1.146 x 10⁴ year.
Explanation:
- The decay of carbon-14 is a first order reaction.
- The rate constant of the reaction (k) in a first order reaction = ln (2)/half-life = 0.693/(5730 year) = 1.21 x 10⁻⁴ year⁻¹.
- The integration law of a first order reaction is:
<em>kt = ln [A₀]/[A]</em>
<em></em>
k is the rate constant = 1.21 x 10⁻⁴ year⁻¹.
t is the time = ??? years.
[A₀] is the initial percentage of carbon-14 = 100.0 %.
[A] is the remaining percentage of carbon-14 = 1/4[A₀] = 25.0 %.
∵ kt = ln [Ao]/[A]
∴ (1.21 x 10⁻⁴ year⁻¹)(t) = ln (100.0%)/[25.0 %]
(1.21 x 10⁻⁴ year⁻¹)(t) = 1.386.
∴ <em>t </em>= 1.386/
(1.21 x 10⁻⁴ year⁻¹) = <em>1.146 x 10⁴ year.</em>
The mole fraction of pentane in the vapor is 0.291
Vapour pressure rises with temperature and is a measurement of a substance's propensity to transform into a gaseous or vapour state. The boiling point of a liquid is the temperature at which the pressure exerted by its surroundings equals the vapour pressure present at the liquid's surface.
The number of moles of a particular component in the solution divided by the overall number of moles in the sample solution is known as the mole fraction.
Using the formula for vapour pressure,
vapour pressure = 
°
× 
+ °
× 
vapour pressure = 151 × 
+ 425 ×
240 = 151 - 151 + 425
240 - 151 = - 151 + 425
89 = 274
=
0.291 =
Therefore, the mole fraction of pentane in the vapor is 0.291
Learn more about vapour pressure here;
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Answer:
88.5 g/m is the molar mass for the gas
Explanation:
We need the Ideal Gases Law equation to solve this:
P . V = n . R . T
Pressure (P) = 10 Torr
We must convert to atm → 10 Torr / 760 Torr = 0.0131 atm
Volume (V) = 255 mL
We must convert to L → 255 mL / 1000 = 0.255 L
n = number of moles
moles = mass in g / molar mass
12.1 mg/ 1000 = 0.0121 g
T° = 25°C + 273K = 298K
R = 0.082 L.atm /mol.K
Let's replace the values
0.0131 atm . 0.255L = 0.0121 g / x . 0.082 L.atm /mol.K . 298K
(0.0131 atm . 0.255L) / (0.082 L.atm /mol.K . 298K) = 0.0121 g / x
1.367×10⁻⁴ /mol = 0.0121 g / x
x = 0.0121 g / 1.367×10⁻⁴ mol = 88.5 g/m
Answer:
hope this helps have a amazing day! :)
Explanation:
Metals are an excellent conductor of electricity and heat because the atoms in the metals form a matrix through which outer electrons can move freely. Instead of orbiting their respective atoms, they form a sea of electrons that surround the positive nuclei of the interacting metal ions.
