Answer:
First, we can test Solution 1. We know that Sodium Hydroxide is a strong base. If we test acids on blue litmus paper, they will turn red. If we test bases on red litmus paper, they will turn blue. So, you can test all the of the solutions- water, sodium hydroxide and hydrochloric acid with blue and red litmus paper. HCl, Hydrochloric acid is an acid, so it will turn blue litmus paper red. It will not turn red litmus blue. The acids will turn blue litmus paper red. The bases will turn red litmus paper blue. Only water is a neutral liquid, which will not turn blue litmus paper red or red litmus paper blue. It will not change the colour of it. Thus, if you test all the solutions with blue and red litmus paper, you will know which solution is water. Water is the only one which is neutral. It is the only solution which cannot change the colour of any litmus paper. Thus, you can identify it very easily.
Answer:
The change in the internal energy of the system -878 J
Explanation:
Given;
energy lost by the system due to heat, Q = -1189 J (negative because energy was lost by the system)
Work done on the system, W = -311 J (negative because work was done on the system)
change in internal energy of the system, Δ U = ?
First law of thermodynamics states that the change in internal energy of a system (ΔU) equals the net heat transfer into the system (Q) minus the net work done by the system (W).
ΔU = Q - W
ΔU = -1189 - (-311)
ΔU = -1189 + 311
ΔU = -878 J
Therefore, the change in the internal energy of the system -878 J
Answer:
The rain falling in New England is 2.29 times more acidic than the one in the American Midwest.
Explanation:
The acidity of a solution depends on the concentration of H⁺ ions ([H⁺]). We can calculate this concentration from the pH using the following expression.
pH = -log ([H⁺])
American Midwest
pH = -log ([H⁺])
5.02 = -log ([H⁺])
[H⁺] = antilog (-5.02) = 9.55 × 10⁻⁶ M
New England
pH = -log ([H⁺])
4.66 = -log ([H⁺])
[H⁺] = antilog (-4.66) = 2.19 × 10⁻⁵ M
The ratio of concentrations is:
![\frac{2.19 \times 10^{-5} M }{9.55 \times 10^{-6} M} =2.29](https://tex.z-dn.net/?f=%5Cfrac%7B2.19%20%5Ctimes%2010%5E%7B-5%7D%20M%20%20%7D%7B9.55%20%5Ctimes%2010%5E%7B-6%7D%20M%7D%20%3D2.29)
The rain falling in New England is 2.29 times more acidic than the one in the American Midwest.
Answer:
The law of conservation of mass states that mass cannot be created or destroyed only transfered. So when a size change takes place the mass is being transfered into something else. During a state change the mass is being transfered into another state of matter. When a substance dissolves into another liquid the mass is still their just into another state.
Explanation:
<u>Answer:</u> The longest wavelength of light is 656.5 nm
<u>Explanation:</u>
For the longest wavelength, the transition should be from n to n+1, where: n = lower energy level
To calculate the wavelength of light, we use Rydberg's Equation:
![\frac{1}{\lambda}=R_H\left(\frac{1}{n_i^2}-\frac{1}{n_f^2} \right )](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B%5Clambda%7D%3DR_H%5Cleft%28%5Cfrac%7B1%7D%7Bn_i%5E2%7D-%5Cfrac%7B1%7D%7Bn_f%5E2%7D%20%5Cright%20%29)
Where,
= Wavelength of radiation
= Rydberg's Constant = ![1.096776\times 10^7m^{-1}](https://tex.z-dn.net/?f=1.096776%5Ctimes%2010%5E7m%5E%7B-1%7D)
= Higher energy level = ![n_i+1=(2+1)=3](https://tex.z-dn.net/?f=n_i%2B1%3D%282%2B1%29%3D3)
= Lower energy level = 2 (Balmer series)
Putting the values in above equation, we get:
![\frac{1}{\lambda }=1.096776\times 10^7m^{-1}\left(\frac{1}{2^2}-\frac{1}{3^2} \right )\\\\\lambda =\frac{1}{1.5233\times 10^6m^{-1}}=6.565\times 10^{-7}m](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B%5Clambda%20%7D%3D1.096776%5Ctimes%2010%5E7m%5E%7B-1%7D%5Cleft%28%5Cfrac%7B1%7D%7B2%5E2%7D-%5Cfrac%7B1%7D%7B3%5E2%7D%20%5Cright%20%29%5C%5C%5C%5C%5Clambda%20%3D%5Cfrac%7B1%7D%7B1.5233%5Ctimes%2010%5E6m%5E%7B-1%7D%7D%3D6.565%5Ctimes%2010%5E%7B-7%7Dm)
Converting this into nanometers, we use the conversion factor:
![1m=10^9nm](https://tex.z-dn.net/?f=1m%3D10%5E9nm)
So, ![6.565\times 10^{-7}m\times (\frac{10^9nm}{1m})=656.5nm](https://tex.z-dn.net/?f=6.565%5Ctimes%2010%5E%7B-7%7Dm%5Ctimes%20%28%5Cfrac%7B10%5E9nm%7D%7B1m%7D%29%3D656.5nm)
Hence, the longest wavelength of light is 656.5 nm