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Setler79 [48]
3 years ago
13

Why is it do rare to experience a total solar eclipse?

Chemistry
1 answer:
deff fn [24]3 years ago
4 0

it only happensonce every 7 years

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posledela
Mitosis is a stage of the cell cycle
7 0
3 years ago
a) Calculatethe molality, m, of an aqueous solution of 1.22 M sucrose, C12H22O11. The density of the solution is 1.12 g/mL.b) Wh
Contact [7]

Answer:

a) 1,74 molal

b) 37,2 %

c) 0,03

Explanation:

We are going to define sucrose as solute, water as solvent and the mix of both, the solution.

Let´s start with the data:

Molarity = M = \frac{1,22 mol solute}{lts solution}

We can assume as a calculus base, 1 liter of solution. So, in 1 liter of solution we have 1,22 moles of solute:

1 lts solution * \frac{1,22 moles solute}{lts solution}=1,22 moles solute

Knowing that the molality (m) is defined as mol of solute/kgs solvent, we have to calculate the mass of solvent on the solution. Remember our calculus base (1 lts of solution). In 1 lts of solution we have 1120 grams of solution.

1 lts solution * \frac{1,12 grs solution}{mL solution}*\frac{1000 mL solution}{1 lts solution} = 1120 grs of solution

With the molecular weight of solute (<em>Sum of: for carbon = 12*12=144; for hydrogen = 1*22=22 and for oxygen = 16*11=176. Final result = 342 grs per mol</em>), we can obtain the mass of solute:

1,22 mol solute*\frac{342 grs solute}{1 mol solute} = 417,24 grs solute

Now, the mass of solvent is: mass solvent = mass of solution - mass of solute. So, we have: 1120 - 417,24 = 702,76 grs of solvent = 0,70276 Kgs of solvent

molality = m = \frac{1,22 mol solute}{0,70276 kgs solvent}= 1,74 molal

For b) question we have that the mass percent of solute is hte ratio between the mass of solute and the mass of solution. So,

%(w/w) = \frac{417,24 grs solute}{1120 grs solution} = 37,2%

For c) question we have that the mole fraction of solute is the ratio between moles of solute and moles of solution. Let's calculate the moles of solution as follows: <em>Moles solution = moles solute + moles solvent.</em> First we have that the moles of solvent are (remember that the molecular weight of water for this calculus is 18 grs per mol):

702,76 grs solvent*\frac{1 mol solvent}{18 grs solvent} = 39,04 moles solvent  

So, we have the moles of solution: 1,22 moles of solute + 39,04 moles of solvent = 40,26 moles of solution

Finally, we have:

Mol frac solute = \frac{1,22 mol solute}{40,26 mol solution}= 0,03

6 0
3 years ago
The number of glyceraldehyde-3-phosphate molecules that would be produced from 24 turns of the calvin cycle would be
SVEN [57.7K]
The Calvin cycle, also called the light-independent or carbon fixation reactions, is the second stage of photosynthesis where water, and carbon dioxide (CO2) from air, are converted into organic compounds (i.e. sugars) using the energy from short-lived electronically excited carriers (ATP and NADPH) for the reactions. These organic compounds can then be used by the producing organism (i.e. plants) and the animals that feed on it. 

One product of the Calvin cycle is the glyceraldehyde-3-phosphate (G3P), which is later on used in the production of glucose and in the regeneration of <span>Ribulose 1,5-bisphosphate (RuBP), which is an organic compound</span> essential to the reactions in the cycle. 

One turn of Calvin Cycle produces 2 G3P molecules, each comprising of 3 carbons. This gives a total of 6 carbons. Five (5) of these carbons will be used to regenerate RuBP and only 1 will be available to form a surplus G3P later on. This surplus G3P will be used for the production of glucose (a 6-carbon sugar). 

Thus, 3 turns of the carbon cycle will produce 1 surplus G3P. There are 8 sets of 3-turns in 24 cycles, therefore, 

                       1 net G3P molecule * 8 sets of 3-turns  = 8 G3P molecules

Therefore, there are 8 net or surplus G3P molecules produced for 24 cycles of the Calvin Cycle. The total G3P molecules produced, including the ones that participated in the regeneration of RuBP would be 48 G3Ps. 

For every 3 turns, 6 G3P molecules are produced, 5 of which will be used in the regeneration of RuBP and 1 will be the net or surplus, to be used for the production of glucose. The 48 G3Ps then come from the calculation, 

                       6 total G3P molecules * 8 sets of 3-turns  = 48 G3P molecules


The figure below shows the products of the cycle after 3 turns (Source: https://ka-perseus-images.s3.amazonaws.com/2f4bdc8f8275834d3f5ef434d93bf16b991b2357.png). 

7 0
3 years ago
The specific heat capacity of graphite is 0.71 J/°C g.
Tom [10]

Answer:

,,mknlmn

Explanation:

'.'.'.

8 0
3 years ago
What does the law of conservation of energy state?
Anarel [89]

Answer:

it states that the total mass of the products are the same as the total mass of the reactants in a chemical reaction.

Explanation:

4 0
3 years ago
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