What are 4 local breezes

Photosynthesis is very important to us. Name 3 different types of ways you benefit from photosynthesis each day

Novay_Z [31]

Breathing as photosynthesis releases oxygen
food as photosynthesis helps the plant to grow

5 0

3 years ago

A weather balloon is filled with helium that occupies a volume of 5.57 104 L at 0.995 atm and 32.0°C. After it is released, it r

Alchen [17]

6.52 × 10⁴ L. (3 sig. fig.)

<h3>Explanation</h3>

Helium is a noble gas. The interaction between two helium molecules is rather weak, which makes the gas rather "ideal."

Consider the ideal gas law:

$P\cdot V = n\cdot R\cdot T$ ,

where

$P$ is the pressure of the gas,
$V$ is the volume of the gas,
$n$ is the number of gas particles in the gas,
$R$ is the ideal gas constant, and
$T$ is the absolute temperature of the gas in degrees Kelvins.

The question is asking for the final volume $V$ of the gas. Rearrange the ideal gas equation for volume:

$V = \dfrac{n \cdot R \cdot T}{P}$ .

Both the temperature of the gas, $T$ , and the pressure on the gas changed in this process. To find the new volume of the gas, change one variable at a time.

Start with the absolute temperature of the gas:

$T_0 = (32.0 + 273.15) \;\text{K} = 305.15\;\text{K}$ ,
$T_1 = (-14.5 + 273.15) \;\text{K} = 258.65\;\text{K}$ .

The volume of the gas is proportional to its temperature if both $n$ and $P$ stay constant.

$n$ won't change unless the balloon leaks, and
consider $P$ to be constant, for calculations that include $T$ .

$V_1 = V_0 \cdot \dfrac{T_1}{T_2} = 5.57\times 10^{4}\;\text{L}\times \dfrac{258.65\;\textbf{K}}{305.15\;\textbf{K}} = 4.72122\times 10^{4}\;\text{L}$ .

Now, keep the temperature at $T_1 =258.65\;\text{K}$ and change the pressure on the gas:

$P_1 = 0.995\;\text{atm}$ ,
$P_2 = 0.720\;\text{atm}$ .

The volume of the gas is proportional to the reciprocal of its absolute temperature $\dfrac{1}{T}$ if both $n$ and $T$ stays constant. In other words,

$V_2 = V_1 \cdot\dfrac{\dfrac{1}{P_2}}{\dfrac{1}{P_1}} = V_1\cdot\dfrac{P_1}{P_2} = 4.72122\times 10^{4}\;\text{L}\times\dfrac{0.995\;\text{atm}}{0.720\;\text{atm}}=6.52\times 10^{4}\;\text{L}$

(3 sig. fig. as in the question.).

See if you get the same result if you hold $T$ constant, change $P$ , and then move on to change $T$ .

6 0

2 years ago

How many grams of ethylene glycol (C2H6O2) must be added to 1.15 kg of water to produce a solution that freezes at -4.46Â°C?

jok3333 [9.3K]

Answer:

232.5 g C2H6O2

Explanation:

The equation you need to use here is ΔTf = i Kf m

Since pure water freezes at 0 C, your ΔTf is just 4.46 C

i = 1 (ethylene glycol is a weak electrolyte)

Kf = molal freezing constant, which for water is 1.86 C/m

m = molality = x mols C2H6O2 / 1.15 kg H2O (don't know the moles of ethylene glycol we're dissolving yet)

Than,

4.46 C = 1.86 C/m (x mol C2H6O2 / 1.15 kg H2O)

Solve for x, you should get x = 2.75 mol C2H6O2

3.75 mol C2H6O2 (62 g C2H6O2 / 1 mol C2H6O2) = 232.5 g C2H6O2

7 0

3 years ago

Element Z has a mass of 430g. Scientists determined it to have a ½ life of 5 years. How many grams of element Z will remain afte

Afina-wow [57]

Answer:

hope this helped youu:)

7 0

2 years ago

What do atom, molecules, and elements have in common

____ [38]

Answer:

Solids, liquids, gases - all matter - are made up of atoms (or other things, like molecules, that are made from atoms)! ELEMENTS are the kinds of atoms that we can have. Carbon is an element, hydrogen is an element, and so is oxygen. ... Atoms can join together - they form bonds together - to make MOLECULES.

6 0

2 years ago