Yes, that is true. in order for it to be a redox reaction, both oxidation and reduction must be occurring.
Answer:
27.60 g urea
Explanation:
The <em>freezing-point depression</em> is expressed by the formula:
In this case,
- ΔT = 5.6 - (-0.9) = 6.5 °C
m is the molality of the urea solution in X (mol urea/kg of X)
First we<u> calculate the molality</u>:
- 6.5 °C = 7.78 °C kg·mol⁻¹ * m
Now we<u> calculate the moles of ure</u>a that were dissolved:
550 g X ⇒ 550 / 1000 = 0.550 kg X
- 0.84 m = mol Urea / 0.550 kg X
Finally we <u>calculate the mass of urea</u>, using its molecular weight:
- 0.46 mol * 60.06 g/mol = 27.60 g urea
A simple way to go about this is that we look at the solubility curve, on the x axis we first look at the temperature and then the corresponding value of solute/100g H2O on the y axis, from the 4 curves above only NaNO3 has a curve that can accommodate 80g of salt at 40 without being Saturated since at 40 degrees it can accommodate 105g of salt to become completely Saturated.
Answer:
Both the initial and final substances are composed of atoms because all matter is composed of atoms. According to the law of conservation of matter, matter is neither created nor destroyed, so we must have the same number and type of atoms after the chemical change as were present before the chemical change.
Explanation:
The atoms that make up your body were produced inside a star and have ... I read once that atoms get recycled so much through the planet that each of ... from William Shakespeare, but I do know this: All of us come from stars. ... If you have gold fillings in your teeth, those atoms came from a star explosion.
Answer:
During photosynthesis SOLAR enerrgy is transformed into CHEMICAL energy.
Explanation:
In nutrition, green plants manufactures their own food which they use for both energy and growth. This is called an autotrophic mode of nutrition.
Therefore, photosynthesis is an autotrophic nutrition in which plant can build sugar by taking carbon dioxide from air and water from the soil. For the synthesis of sugar like glucose, carbon dioxide provides carbon
and oxygen whereas water molecules provide hydrogen. The plant builds sugar molecules from these simple compounds. Enzymes needed for this purpose are present in the cells and energy is trapped by chlorophyll from sunlight. This process is summarised in the equation below:
Sunlight (solar)
6CO2 + 6H2O--------------------> C6H12O6 + 6O2
From the equation, Carbon dioxide, water and sunlight (SOLAR energy) is the raw materials needed to produce Glucose and oxygen (CHEMICAL energy) as by products.