The correct answer to this open question is the following.
Two examples of how engineers use their knowledge of atoms to create new technologies would be the following.
1.- Engineers can develop new medicines for chronic diseases when they use their knowledge about atoms. With new technologies and different scientific approaches, this new molecular medicine can be more effective in the treatment of terrible diseases that affect humans. The challenge lies in how to make these new medicines more affordable to all kinds of people, not only rich people.
2.- Engineers can also apply their knowledge about atoms to improve the water conditions so more people can have freshwater. Engineers that specialize in the environment can research the properties of water molecules and atoms, so they can develop new ways to purify and improve the quality of water, that we know that water scarcity is a major problem in many parts of the world.
Sodium Chloride is 0.4948 kJ/mol while Sodium Thiosulfate Pentahydrate is 0.2059 kJ/mol. Therefore, Sodium Chloride could store more energy on a per gram basis.
Answer:
a) CaF₂.
b) 7.81g of CaF₂ are present.
Explanation:
a) The calcium ion has as charge Ca²⁺ and fluoride ion is F⁻, that means formula unit is:
CaF₂
b) 1 molecule of CaF₂ contains 2 anions, F⁻. Thus, the moles of CaF₂ is:
1.2x10²³ anions * (1 moleculeCaF₂ / 2 anions) = 6x10²² molecules of CaF₂
6.022x10²³ molecules = 1mol:
6x10²² molecules of CaF₂ * (1mol / 6.022x10²³molecules) = 0.10 moles CaF₂.
1 mole of CaF₂ has a mass of 78.07g:
0.10 moles CaF₂ * (78.07g / mol) =
7.81g of CaF₂ are present
Ni(OH)2+H2SO4=NiSO4+2H2O
Double Replacement Reaction
The first thing you need to do is convert mL into L
so (175 mL)(.001L/1mL)=.175L then you multiply by the Molarity of H3PO4 which is 3.5mol/L so (.175L)(3.5mol/L)=.6125 mol H3PO4, and since it wants the answer in grams you then multiply (.6125molH3PO4) by the molar mass of H3P04 which is about 97.99g and your answer is 60.02g which is about 60 grams of H3PO4. Hope this helped
