Answer:
- % Cobalt (II) Nitrate = 30.62%
Explanation:
To calculate mass percent, first we need to <u>calculate the total mass of the mixture</u>:
- Mass Water ⇒ 0.350 kg Water = 350 g water
- Mass Ammonia⇒We use ammonia's molar mass⇒5.4 mol * 17 g/mol = 91.8 g
- Mass cobalt (II) nitrate ⇒ 195.0 g
Total Mass = Mass Water + Mass Ammonia + Mass Cobalt Nitrate
- Total Mass = 350 g+ 91.8 g+ 195 g = 636.8 g
To calculate each component's mass percent, we divide its mass by the total mass and multiply by 100:
- % Water ⇒ 350/636.8 * 100% = 54.96%
- % Ammonia ⇒ 91.8/636.8 * 100% = 0.14%
- % Cobalt (II) Nitrate ⇒ 195/636.8 * 100% = 30.62%
The periodic table of elements arranges all of the known chemical elements in an informative array. Elements are arranged from left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass. The rows are called periods.
The effective nuclear charge is an innate property of a specific element. It is the pull of force that an electron feels from the nucleus. It is related to the valence electron by the equation: Z* = Z-S, where Z* is the effective nuclear charge, Z is the atomic number and S is the shielding constant.
For the following elements in the choices, these are their values of Z*:
Aluminum - +12.591
Beryllium - +1.912
Hydrogen - +1
Carbon - +4
The effective nuclear charge of Boron is +3. Thus, the answers are Aluminum and Carbon.
Answer:
Meteorites are consensually considered to be involved in the origin of life on this Planet for several functions and at different levels: (i) as providers of impact energy during their passage through the atmosphere; (ii) as agents of geodynamics, intended both as starters of the Earth’s tectonics and as activators of local hydrothermal systems upon their fall; (iii) as sources of organic materials, at varying levels of limited complexity; and (iv) as catalysts.
Explanation:
1) Molecular formula of ammonium sulfide
(NH4)2 S
2) That means that there are 2*4 = 8 atoms of hydrogen in each molecule of ammoium sulfide, so in 5.20 mol of molecules will be 8 * 5.20 mol = 41.6 moles of atoms of hydrogen
3) To pass to number of atoms multiply by Avogadro's number: 6.022 * 10^23
41.6 moles * 6.022 * 10^23 atoms / mol = 250.5 * 10^23 = 2.50 * 10^25 atoms
Answer: 2.50 * 10^25
