Answer:
Roman numbers are oxidation state of the metals
Because some elements of metals show more than one oxidation state like iron Fe2+ in ferrous and Fe3+ in ferric.
Explanation:
Answer: A volume of 455 mL from 0.550 M KBr solution can be made from 100.0 mL of 2.50 M KBr.
Explanation:
Given: 
= ?, 
= 0.55 M
= 100.0 mL, 
= 2.50 M
Formula used to calculate the volume of KBr is as follows.
Substitute the values into above formula as follows.
Thus, we can conclude that a volume of 455 mL from 0.550 M KBr solution can be made from 100.0 mL of 2.50 M KBr.
Answer:
60.02 g.
Explanation:
- It is clear from the balanced equation:
<em>Mg + 2HCl → MgCl₂ + H₂.
</em>
that 1.0 mole of Mg reacts with 2.0 moles of HCl to produce 1.0 mole of MgCl₂ and 1.0 moles of H₂.
- 20.0 g of Mg reacts with excess HCl. To calculate the no. of grams of HCl that reacted, we should calculate the no. of moles of Mg:
<em>no. of moles of Mg = mass/atomic mass</em> = (20.0 g)/(24.3 g/mol) = 0.823 mol.
- From the balanced equation; every 1.0 mol of Mg reacts with 2 moles of HCl.
∴ 0.833 mol of Mg will react with (2 x 0.833 mol = 1.646 mol) of HCl.
<em>∴ The mass of reacted HCl = no. of moles x molar mass</em> = (1.646 mol)(36.46 g/mol) = <em>60.02 g.</em>
Explanation:
Methane molecule is depicted here
The answer is 53.8 kJ.
Solution:There are two major steps in converting ice to liquid water. It begins with a phase change when ice melts at 0.0°C, and then a temperature change when the liquid water rises in temperature from zero to 32°C.
The amount of heat involved with the phase change melting is given by
q = (mass of water) (ΔHfus)
= (115.0 g)(334 J/g)
= 38410 J = 38.41 kJ
The amount of heat involved with temperature change is
q = mcΔT
= (115.0g)(4.184J/g°C)(32°C - 0.0°C)
= 15397.12 J = 15.39712 kJ
Summing up the two values gives the total heat required to convert ice to liquid water:
q = 38.41 kJ + 15.39712 kJ= 53.8 kJ
