Why does 4.03/0.0000035 = 1.2 x 106, instead of a different number of significant figures?
1 answer:
Explanations:- As per the significant figures rule, In multiplication and division, we go with least number of sig figs.
4.03 has three sig figs where as 0.0000035 has two sig figs only, The zeros in this number are not sig figs as they are just holding the place values. As the least number of sig figs here is two, the answer needs to be reported with two sig figs only.
You might be interested in
Answer: Option (c) is the correct answer.
Explanation:
A chemical reaction is defined as the reaction where a chemical bond will break in order to form a new bond due to the formation of a new substance.
For example,
Here, NaCl is the new substance that is formed. A chemical reaction will always bring change in chemical composition of a substance.
The production of hydrogen gas from water, the tarnishing of a copper penny, charging a cellular phone and burning a plastic water bottle are all chemical reactions.
Whereas a reaction where no change in chemical composition of a substance takes place is known as a physical reaction.
For example, chopping a log into sawdust will change the shape but it will not bring any change in chemical composition of the substance.
Thus, we can conclude that in the following list, only chopping a log into sawdust is not an example of a chemical reaction.
Answer:
Total pressure = 0,806 atm
Partial pressure of CH₄: 0,037 atm
Partial pressure of Cl₂: 0,396 atm
Partial pressure of CH₃Cl: 0,125 atm
Partial pressure of HCl: 0,125 atm
Partial pressure of Cl⁻: 0,125 atm
Explanation:
For the reaction:
2CH₄(g)+3Cl₂(g)⟶2CH₃Cl(g)+2HCl(g)+2Cl⁻(g)
295 mL≡ 0,295L of methane at STP are:
n = PV/RT
P = 1 atm; V = 0,295L; R = 0,082atmL/molK; T = 273K.
moles of methane: 0,0132 moles
For 725 mL of chlorine ≡ 0,725L
moles of chlorine at STP are: ≡ 0,0324 moles
For a complete reaction of 0,0132 moles of CH₄:
0,0132 mol CH₄× = <em>0,0198 moles</em>
The reaction reaches 77%, moles of Cl₂ that react are: 0,0198×77% = 0,0153 mol
As you have 0,0324 moles of Cl₂, moles that will not react are:
0,0324 - 0,0153 = <em>0,0171 mol Cl₂</em>
As the reaction reaches 77% completion, moles of CH₄ that react are:
0,0132×77% =<em> 0,0102 moles of CH₄ And the moles that don't react are </em><em>0,00300 mol</em>
Thus, moles of each compound are:
0,0102 moles of CH₄×= <em>0,0153 mol + 0,0171 mol = 0,0324 mol Cl₂</em>
0,0102 moles of CH₄×= <em>0,0102 mol CH₄</em>
0,0102 moles of CH₄×= <em>0,0102 mol HCl</em>
0,0102 moles of CH₄×= <em>0,0102 mol Cl⁻</em>
Total pressure using:
P = nRT/V
Where: n = 0,0102mol×3+0,0324mol + 0,0030mol = 0,0660mol; R = 0,082 atmL/molK; T = 298K; V = 2L
Total pressure = 0,806 atm
Partial pressure of CH₄: 0,037 atm
Partial pressure of Cl₂: 0,396 atm
Partial pressure of CH₃Cl: 0,125 atm
Partial pressure of HCl: 0,125 atm
Partial pressure of Cl⁻: 0,125 atm
<em>-To obtain partial pressure you change the moles for each compound-</em>
<em />
I hope it helps!