Answer:
713.51 N/m
Explanation:
Hook's Law: This law states that provided the elastic limit is not exceeded, the extension in an elastic material is directly proportional to the applied force.
From hook's law,
F = ke ...........................Equation 1
Where F = Force exerted on the bowstring, e = Extension/compression of the bowstring, k = Spring constant of the bow.
Make k the subject of the equation,
k = F/e ............................ Equation 2
Given: F = 264 N, e = 0.37 m.
Substitute into equation 2
k = 264/0.37
k = 713.51 N/m
Hence the spring constant of the bow = 713.51 N/m
A is obviously out because it leads to a volume of 125.0 milliliters of the new solution and gives you a lower concentration than you were aiming for.
D is out because you are adding 75 milliliters of the stock solution, so your concentration would be too high. You only need 25.0 milometers of stock solution per 100 milliliters of the new solution.
C is also out because it leads to 50.0 milliliters stock solution per 100 milliliters of the new solution and hence the wrong concentration.
B is by default the correct answer. It also details the correct technique. First you add the stock solution (This you know from your calculations to be 25 milliliters.) then you add the water up to the volume you needed. (Because the calculations only tell you the total volume of water not what you need to add) You also add the water last so you can rinse the neck of the flask to make sure you also get all the stock solution residue into the stock solution.
I would add the final step of stirring, but B is the only answer that can be correct.
B
mass of solute - 4.0 g
mass of solution - 100g + 4.0g = 104g
4/104 = 0.03846
0.03846 • 100 = 3.8%
Answer:
The correct option here is the first option
Explanation:
Covalent bond is the bond that involves the sharing of electrons between the participating atoms. The electrons (in the outermost shells of the atoms) that are involved this sharing are called the "shared pair" while those electrons (in the outermost shells of the atoms) that are not involved in this sharing are called the "lone pair". Bonding eventually leads to each of the participating atoms achieving it's octet configuration.
Carbon will bind covalently with fluorine (to form carbon tetrafluoride) with each of the electrons on the outermost shell of the carbon been shared covalently with fluorine atoms (that also requires just one electron to achieve it's octet configuration). Thus, at the end, we would have one carbon atom being covalently linked to four flourine atoms.
