Answer:
- second choice:<em><u> 1.0 g of the solution contains 15 × 10⁻⁶ g of benzene.</u></em>
Explanation:
ppm is a unit of concentration that means parts per million. In grams that is grams of solute per one million (10⁶) grams of solution.
Then, <em>15 ppm of benzene</em> means that there are 15 grams of benzen in 1,000,000 grams of solution.
That leads to:
- 1,000,000 g solution / 15 g benzene
Multiplying numerator and denominator by 10⁻⁶ you find:
- 1,000,000 × 10⁻⁶ g solution / (15 × 10⁻⁶ g benzene)
Simplifying:
- 1.0 g solution / (15 × 10⁻⁶ g benzene)
Which is read as 1.0 g of the solution contains 15 × 10⁻⁶ g of benzene, i.e. the second answer choice.
"The reaction is exothermic and ΔH is negative" can be understood about the reaction and the enthalpy change (ΔH) during the reaction.
<u>Option: D</u>
<u>Explanation:</u>
When the reaction is positive, the process becomes endothermic, i.e. heat appears to be consumed by the system because the reaction products are more enthalpic than the reactants. When the reaction is negative, on the other hand, the process is exothermic, which is the total decrease in enthalpy is caused by heat production. Here the initial temperature is 21.0 C but increase in final temperature to 38.8 C, because if some processes require heat, others must give off heat when they take place.
The molar mass of a, b and c at STP is calculated as below
At STP T is always= 273 Kelvin and ,P= 1.0 atm
by use of ideal gas equation that is PV =nRT
n(number of moles) = mass/molar mass therefore replace n in the ideal gas equation
that is Pv = (mass/molar mass)RT
multiply both side by molar mass and then divide by Pv to make molar mass the subject of the formula
that is molar mass = (mass x RT)/ PV
density is always = mass/volume
therefore by replacing mass/volume in the equation by density the equation
molar mass=( density xRT)/P where R = 0.082 L.atm/mol.K
the molar mass for a
= (1.25 g/l x0.082 L.atm/mol.k x273k)/1.0atm = 28g/mol
the molar mass of b
=(2.86g/l x0.082L.atm/mol.k x273 k) /1.0 atm = 64 g/mol
the molar mass of c
=0.714g/l x0.082 L.atm/mol.K x273 K) 1.0atm= 16 g/mol
therefore the
gas a is nitrogen N2 since 14 x2= 28 g/mol
gas b =SO2 since 32 +(16x2)= 64g/mol
gas c = methaneCH4 since 12+(1x4) = 16 g/mol
Answer: Hello the compound is missing but I was able to get the Full question and missing compound . ( compound = copper sulfate )
<em>answer</em> : statement ; 2 , 3 and 5
Explanation:
The true statements regarding the coordination compound ( copper sulfate ) are :
- The ligand must have at least one unshared pair of valence electrons in order to covalently bond with transition metal in the coordination compound ( statement 2 )
- Ethanol was used during crystallization of the coordination compound because the compound is soluble in ethanol ( statement 3 )
- The colors of many coordination compounds are the result of light absorption by the d electrons on the transition metal ( statement 5 )
During the coordination of compounds dative bonds exits between the transition metals and the Ligands molecules
Answer:
Law of conservation of mass
Ernest Rutherford
Explanation:
The basic law of behavior of matter that states that "mass is neither created nor destroyed in a chemical reaction or physical change".
This is the law of conservation of mass. It is very essential in understanding most chemical reaction. Also, in quantitative analysis, this law is pivotal.
Ernest Rutherford was the scientist that stated that the nucleus is made up of positive charge. It was not until James Chadwick in 1932 discovered the neutron that we had an understanding of this nuclear component.
Rutherford surmised from his experiment that because most the alpha particles passed through the thin Gold foil and just a tiny fraction was deflected back, the atom is made is made up of small nucleus that is positively charged.
