Answer:
Empirical SiCl3
Molecular Si2Cl6
Explanation:
Since it contains 79.1% chlorine, this means it contains (100 - 79.1)% silicon = 20.9% chlorine
To get the empirical formula, we firstly need to know the atomic masses of both chlorine and silicon. This is 35.5 and 28
We then divide the percentage abundances by the corresponding atomic masses.
Cl = 79.1/35.5 = 2.23
Si = 20.9/28 = 0.75
We then divide by the smallest, which is 0.75
Cl = 2.23/0.75 = 3
Si = 0.75/0.75 = 1
The empirical formula is thus SiCl3
To get the molecular formula:
(28+3(35.5))n = 269
134.5n = 269
n = 269/134.5 = 2
The molecular formula is Si2Cl6
Answer:
45 °C.
Explanation:
From the question given above, the following data were obtained:
Heat (Q) = 1125 J
Mass (M) = 250 g
Final temperature (T₂) = 55 °C
Specific heat capacity (C) = 0.45 J/gºC
Initial temperature (T₁) =?
The initial temperature of the iron can be obtained as illustrated below:
Q = MC(T₂ – T₁)
1125 = 250 × 0.45 (55 – T₁)
1125 = 112.5 (55 – T₁)
Divide both side by 112.5
1125/112.5 = 55 – T₁
10 = 55 – T₁
Collect like terms
10 – 55 = –T₁
–45 = –T₁
Multiply through by –1
45 = T₁
T₁ = 45 °C
Therefore, the initial temperature of the iron is 45 °C
Answer: 2 atoms
Explanation: A molecular formula of the compound carbon dioxide is CO 2 . One molecule of carbon dioxide consists of 1 atom of carbon and 2 atoms of oxygen.
Answer:
Explanation:
Hello,
In this case, considering the given chemical reaction, we can use the molar mass of octane (114.23 g/mol) and the 2:16 molar ratio with carbon dioxide to compute the emitted moles of CO2 to the atmosphere via the following stoichiometric procedure:
Which also corresponds to the following mass:
Best regards.
Answer:
The molarity of a MnO4- solution
= 0.0342 M
Explanation:
Equation of reaction:
5Fe2 (aq) MnO4-(aq) 8H (aq) ---> 5Fe3 (aq) Mn2 (aq) 4H2O(l)
This is an example of redox titration.
Using titration formula:
CAVA/CBVA = NA/NB
where CA is the molarity of Fe2+ = (0.134 M)
CB is the molarity of MnO4- = (?????)
VA is the volume of Fe2+ = (30mL)
VB is the volume of MnO4- =(23.5mL)
NA is the numeric coefficient of Fe2+ in the equation of reaction = ( 5 )
NB is the numeric coefficient of MnO4- in the equation of reaction =(1)
Substituting the values into the formula;
0.134×30/CB×23.5 = 5/1
Therefore CB = 0.134×30/23.5×5
= 0.0342 M
