Answer:
Yes
Explanation:
Scientific laws must always be accompanied by theories. Without theories, laws cannot be formed. In other words, scientific laws are made from scientific theories.
<em>When a hypothesis has been tested by several independent researchers and found to be true, this leads to the development of a theory. A theory becomes a law when it is able to hold true against a wide range of similar phenomena.</em>
Answer:
the bacteria increase in number and use up the dissolved oxygen in the water. When the dissolved oxygen content decreases, many fish and aquatic insects cannot survive. This results in a dead area. Algal blooms may also be of concern as some species of algae produce neurotoxins.Explanation:
Answer:
53.4 % is the percent yield
Explanation:
This is the reaction:
C₆H₆ + Cl₂ → C₆H₅Cl + HCl
First of all we need to know the moles of benzene we used
39 g . 1 mol / 78 g = 0.5 moles
Ratio is 1:1 so 1 mol of benzene produces 1 mol of chloride
0.5 moles of chloride were produced by 0.5 moles of benzene
We must calculate the mass of chloride we produced
0.5 mol . 112.45 g / 1 mol = 56.2g
Let's calculate the percent yield
(Yield produced / Theoretical yield ) . 100
(30 g / 56.2 g) . 100 = 53.4 %
Answer:
Explanation:
Volume of cylinder = πr²h where r is radius of cylinder, h is height of cylinder
r = d/2 = 21/2 = 10.5 cm; h = 25.2 cm
volume of cylinder = (22 * 10.5 cm * 10.5 cm * 25.2 cm) / 7
volume = 8731.8 cm³ = 8.7318 L
Using the ideal gas equation, PV = nRT
P = 4.00 MPa = 4.0 * 10³ kPa, V = 8.7318 L, R = 8.314 L.kPa/mol.K,
n = mass / molar mass
where mass = 0.474 kg or 474 g, molar mass of BF₃= 68 g/mol
n = 474 g / 68 g/mol = 6.9706 moles
making T subject of formula in the ideal gas equation;
T = PV/nR
T = (4.0 * 10³ kPa * 8.7318 L)/(6.9706 mol * 8.314 L.kPa/mol.K)
T = 602.675 K
T in °C = K - 273.15
T = 602.675 -273.15 = 329.5 °C
T = 330 °C
Answer:
Precipitate
Explanation:
Precipitation is actually a chemical reaction that occurs when a solid form is produced from a solution. The solid form is called the precipitate if precipitation occurs in a liquid solution. Precipitates formed are generally, insoluble. This type of reaction can be used to remove salts from a solution, like in the process of purification.