Answer:
0.136g
Explanation:
A student dissolved 5.00 g of Co(NO3)2 in enough water to make 100. mL of stock solution. He took 4.00 mL of the stock solution and then diluted it with water to give 275. mL of a final solution. How many grams of NO3- ion are there in the final solution?

Initial mole of Co(NO3)2 

Mole of Co(NO3)2 in final solution

Mole of NO3- in final solution = 2 x Mole of Co(NO3)2

Mass of NO3- in final solution is mole x Molar mass of NO3

Answer:
0.374 g
Explanation:
Hello,
Since both the molarity and the volume allows us to know the moles of potassium permanganate, and we already have the balanced chemical reaction, the stoichiometric procedure that is attached in the picture, is developed to substantiate the the titrated mass of hydrogen peroxide was 0.374 g.
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Answer:700 nm corresponded to light in the red range and 450 nm corresponded to light in the blue range.
Explanation:The wavelengths of the visible spectrum are usually between 400 nm and 700 nmn with the the rays of red light having a longer wavelength, and blue light rays having shorter wavelengths. The red light has a low frequency of about 405–480 THz and , blue light has a higher frequency in the range of 620–680 THz. This is due to the inverse relationship between wavelength and frequency which also occurs betwwn wavelength and energy of light rays with the red light having less photon energy of about 1.65–2.00 eV and the blue light with high energy photons of about 2.64–2.75 eV.
Red light can be employed in the photosynthesis in plants as it helps in formation of flowers and the production of fruits. Blue light also is important in the production of chlorophyll and can cause a healthy and strong stem and leaves in excess exposure.
Balanced chemical reaction: 2Na(s) + F₂(g) → 2NaF(s) + energy.
This is exothermic reaction (energy or heat is released), because reactants have higher energy than products of reaction.
In ionic salt sodium fluoride (NaF), fluorine has electronegativity approximately χ = 4 and sodium χ = 1 (Δχ = 4 - 1; Δχ = 3), fluorine attracts electron and it has negative charge and sodium has positive charge.
I believe the correct answer is "<span>d. releases, exothermic". When water evaporates, it is water releasing heat and energy, making it an exothermic reaction. Exothermic is defined as a reaction that releases heat with it.
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