Answer:
its letter b
Explanation:
it represents the spectrum of stars
1.For each of the following, give the name of an element from Period 4 (potassium to krypton), which matches the description.
Elements may be used once, more than once or not all.. Single line text.
(1 Point)
an element that reacts with water to produce a lilac flame
2.For each of the following, give the name of an element from Period 4 (potassium to krypton), which matches the description.
Elements may be used once, more than once or not all.. Single line text.
(1 Point)
an element used as an inert atmosphere
3.For each of the following, give the name of an element from Period 4 (potassium to krypton), which matches the description.
Elements may be used once, more than once or not all.. Single line text.
(1 Point)
an element that has a valency of 3
4.Write a balanced chemical equation for the reaction between potassium and water. (Non-anonymous question). .
(1 Point)
Upload file
File number limit: 1Single file size limit: 10MBAllowed file types: Word, Excel, PPT, PDF, Image, Video, Audio
5.For each of the following, give the name of an element from Period 4 (potassium to krypton), which matches the description.
Elements may be used once, more than once or not all.. Single line text.
(1 Point)
an element with a fixed valency of 2 that not is not in group 2
Help
Answer:
Mass = 9.58 g
Explanation:
Given data:
Mass of Fe₂O₃ formed = ?
Mass of Fe = 6.7 g
Solution:
Chemical equation:
4Fe + 3O₂ → 2Fe₂O₃
Number of moles of Fe:
Number of moles = mass/molar mass
Number of moles = 6.7 g/ 55.8 g/mol
Number of moles = 0.12 mol
now we will compare the moles of Fe and Fe₂O₃.
Fe : Fe₂O₃
4 : 2
0.12 : 2/4×0.12 = 0.06 mol
Mass of Fe₂O₃:
Mass = number of moles × molar mass
Mass = 0.06 mol × 159.69 g/mol
Mass = 9.58 g
Answer:
0.4
The efficiency is defined as the work done divided by the heat provided at Th. ε = W/Qh = 400 J/1000 J = 0.4 The Carnot efficiency is given in terms of the high and low temperatures.
Hope this helps, please let me know if it is wrong.
Answer:
The reaction is endothermic
Explanation:
we know that the reactants had to get energy from its surroundings which means that the reaction is endothermic
