Answer:
Q = 2.60 • 
J
Explanation:
Our specific heat capacity equation is:
Q = mC∆T
Q is the energy in joules.
m is the mass of the substance.
∆T is the temperature chance.
Let's plug in what we know.
- We have 76.0 g of octane
- The specific heat capacity of octane is 2.22 J/(g•K)
- The temperature increases from 10.6º to 26.0º (a 15.4º increase)
Q = 76.0(2.22)(15.4)
Multiply.
Q = 2598.288
We want three significant figures.
Q = 2.60 •
or
Q = 2590 J
Hope this helps!
1070 hours.
1 mole of iron-59 would mass 59 grams, so 0.133 picograms would be 0.133x10^-12 / 59 = 2.25x10^-15 moles of iron-59. Multiplying by Avogadro's number, we can determine the number of atoms of iron-59 we have, so: 2.25x10^-15 * 6.02214x10^23 = 1.35x10^9
Since we have 242 decays over a period of 1 second, we can divide the
number of atoms left by the original number of atoms
(1350000000 - 242)/1350000000
= 1349999758/1350000000
= 0.999999820740741
And calculate the logarithm to base 2 of that quotient.
ln(0.999999820740741)/ln(2)
= -1.79259275281191x10^-7/0.693147180559945
= -2.58616467481524x10^-7
The reciprocal of this number will be the half life in seconds. So
-1/2.58616467481524x10^-7
= -3866729.79388461
And dividing by 3600 (number of seconds in an hour) will give the half-life in
hours.
-3866729.79388461 / 3600 = -1074.091609
So the half life in hours to 3 significant figures is 1070 hours.
Dividing that figure by 24 gives a half life of 44.58 days which is in pretty close agreement to the official half-life of 44.495 days for iron-59.
Answer:
Moles of magnesium chloride can be produced are 0.2 moles
Explanation:
The reaction of Mg with Cl2 is:
Mg + Cl₂ → MgCl₂
<em>Where 1 mole of Mg reacts per mole of Cl₂ to produce MgCl₂.</em>
<em />
As the reaction is 1:1, we need to convert the mass of both Mg and Cl₂ to moles. The lower number of moles will determine the moles of MgCl₂ that will be produced:
<em>Moles Mg -Molar mass: 24.3g/mol-:</em>
4.86g * (1mol / 24.3g) = 0.2 moles Mg
<em>Moles Cl₂ -Molar mass: 24.3g/mol-:</em>
21.27g * (1mol / 70.9g) = 0.3 moles Cl₂
As moles of Mg < moles of Cl₂, Mg is limiting reactant and moles of magnesium chloride can be produced are 0.2 moles
Explanation:
Hybridization of O in 
So, water molecule has four hybrid orbitals.
Two hybrid orbitals form 2 sigma bond with two H atoms.
Remaining two hybrid orbitals are occupied by two lone pairs.
Because of lone pair-lone pair repulsion, shape of 
becomes bent.
Water molecule is polar because of difference in eletronegativities of O and H.
O is more electronegative as comapared to hydrogen. So bonding electrons get attracted towards O atom which results in the development of partial negative charge on O atom and partial positive charge on H atoms.
Because of development of partial negative and partial positive charge, water molecule becomes polar.
When elements transfer electrons from a cation and an anion it called ionic bond.
