Answer:
6.23 x 10^23 molecules
Explanation:
First find the number of moles of BH3 from the information given. We know the amount of grams present and we can find the molar mass which is 13.84.
We know that moles is grams divided by molar mass so we get 14.32/13.84 which is 1.03 moles.
Finally, to figure out the number of molecules, we multiply 1.03 by Avogadro's number which is 6.022x10^23 and we get 6.23x10^23 molecules.
Answer: Rutherford's model was the first propose of the existence of small, dense nucleus's.
Explanation: The atom, as described by Ernest Rutherford, has a tiny, massive core called the nucleus. The nucleus has a positive charge. Electrons are particles with a negative charge. Electrons orbit the nucleus. The empty space between the nucleus and the electrons takes up most of the volume of the atom.
Answer:
The answer is 0.023 moles of phosphorus
Explanation:
The 15-15-15 fertilizer is a fertilizer of great versatility, made with nitrogen, phosphorus and potassium, which makes it one of the fertilizers most used for fertilizer in the sowing plant, thus covering the crop requirements from planting. .
This fertilizer consists of 14.25% phosphorus pentoxide (P2O5). Therefore, we have to remove 14.25% at 10 grams of 15-15-15 fertilizer to calculate the moles of phosphorus. As follows:
Grams of P2O5 = 10 g x 0.1425 = 1.425 g
We calculate the molecular weight of phosphorus. We use the periodic table:
Phosphorus molecular weight = 2 x 30.97 = 61.94 g/mol
Now we calculate the moles of phosphorus in the fertilizer:
Phosphorus moles = 1,425 g/61.94 g/mol = 0.023 moles
Answer:- 475 mL.
Solution:- It's based on Boyle's gas law. At constant temperature, "The volume of the gas is inversely proportional to the pressure."
Equation for this law is written as:
P and V stands for pressure and volume where as the subscripts 1 and 2 are for initial and final values.
Initial pressure is 6.20 atm and it asks to calculate the initial volume. Final pressure is 9.150 atm and the final volume is 322 mL.
Let's plug in the values in the equation and solve it for initial volume:
On dividing both sides by 6.20 atm:
= 475 mL
So, the originally the gas container volume was 475 mL.
Answer:
The correct answer is - hard water reacts to form the calcium or magnesium salt of the organic acid of the soap.
Explanation:
Soaps are made up of fatty acids or oils by treating with strong alkali and are salts of sodium and potassium. Hard water, on the other hand, has a high concentration of minerals in comparison to soft water. When hard water and soap are mixed together the salts of the minerals like Ca2+ and Mg2+ ions present in hard water react with fatty acids of the soap.
The sodium salts are changed to the salts of calcium and magnesium which are precipitated to an insoluble substance. The insoluble salts of the calcium or magnesium dirt stick on the clothes thus cleaning ability of soap is reduced.