1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Ivan
3 years ago
7

Reasons Sharecropping Developed Which of the following were reasons why sharecropping developed?

Chemistry
1 answer:
egoroff_w [7]3 years ago
3 0

Answer:

A,B

Explanation:

You might be interested in
Determine the mass of sodium carbonate required to produce 23.4g of sodium chloride when it reacts with excess hydrochloric acid
Leni [432]
The balanced chemical reaction for the described reaction above is,
                          Na2CO3 + 2HCl ---> 2NaCl + H2CO3
From the reaction, 1 mole of Na2CO3 is needed to produce 2 moles of NaCl. In terms of mass, 106 grams of Na2CO3 are needed to produce 116.9 grams of NaCl. From this,
                (23.4 g NaCl) x (106 g Na2CO3 / 116.9 NaCl = 21.22 g Na2CO3
Thus, approximately 21.22 g Na2CO3 is needed for the desired reaction. 
8 0
3 years ago
What is the definition of lead in chemistry
abruzzese [7]

Answer:

Lead is a chemical element with the symbol Pb (from the Latin plumbum) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point.

Explanation:

6 0
3 years ago
How many pi bonds are present in a molecule of HCP?
Anestetic [448]

Answer:

2

Explanation:

6 0
3 years ago
You made hypochlorous acid (HOCI) by mixing bleach (NaOCI) with:
Annette [7]

<u>Answer:</u> When bleach is mixed with water, it produces hypochlorous acid.

<u>Explanation:</u>

The chemical name for bleach is sodium hypochlorite. When this compound is reacted with water, it produces hypochlorous acid and sodium hydroxide.

The chemical equation for the reaction of sodium hypochlorite and water follows:

NaOCl+H_2O\rightarrow HOCl+NaOH

By Stoichiometry of the reaction:

1 mole of sodium hypochlorite reacts with 1 mole of water to produce 1 mole of hypochlorous acid and 1 mole of sodium hydroxide.

Hence, when bleach is mixed with water, it produces hypochlorous acid.

6 0
3 years ago
At what temperature is the following reaction feasible: HCl(g) + NH3(g) -&gt; NH4Cl(s)?
Nutka1998 [239]
Energy is distributed not just in translational KE, but also in rotation, vibration and also distributed in electronic energy levels (if input great enough, bond breaks).

All four forms of energy are quantised and the quanta ‘gap’ differences increases from trans. KE ==> electronic.

Entropy (S) and energy distribution: The energy is distributed amongst the energy levels in the particles to maximise their entropy.

Entropy is a measure of both the way the particles are arranged AND the ways the quanta of energy can be arranged.

We can apply ΔSθsys/surr/tot ideas to chemical changes to test feasibility of a reaction:

ΔSθtot = ΔSθsys +  ΔSθsurr

ΔSθtot must be >=0 for a chemical change to be feasible.

For example: CaCO3(s) ==> CaO(s) + CO2(g) 

ΔSθsys = ΣSθproducts – ΣSθreactants 

ΔSθsys = SθCaO(s) + SθCO2(g) – SθCaCO3(s) 

ΔSθsurr is –ΔHθ/T(K) and ΔH is very endothermic (very +ve),

Now ΔSθsys is approximately constant with temperature and at room temperature the ΔSθsurr term is too negative for ΔSθtot to be plus overall.

But, as the temperature is raised, the ΔSθsurr term becomes less negative and eventually at about 800oCΔSθtot becomes plus overall (and ΔGθ becomes negative), so the decomposition is now chemically, and 'commercially' feasible in a lime kiln.

CaCO3(s) ==> CaO(s) + CO2(g)  ΔHθ = +179 kJ mol–1  (very endothermic)

This important industrial reaction for converting limestone (calcium carbonate) to lime (calcium oxide) has to be performed at high temperatures in a specially designed limekiln – which these days, basically consists of a huge rotating angled ceramic lined steel tube in which a mixture of limestone plus coal/coke/oil/gas? is fed in at one end and lime collected at the lower end. The mixture is ignited and excess air blasted through to burn the coal/coke and maintain a high operating temperature.
ΔSθsys = ΣSθproducts – ΣSθreactants
ΔSθsys = SθCaO(s) + SθCO2(g) – SθCaCO3(s) = (40.0) + (214.0) – (92.9) = +161.0 J mol–1 K–1
ΔSθsurr is –ΔHθ/T = –(179000/T)
ΔSθtot = ΔSθsys +  ΔSθsurr
ΔSθtot = (+161) + (–179000/T) = 161 – 179000/T
If we then substitute various values of T (in Kelvin) you can calculate when the reaction becomes feasible.
For T = 298K (room temperature)

ΔSθtot = 161 – 179000/298 = –439.7 J mol–1 K–1, no good, negative entropy change

For T = 500K (fairly high temperature for an industrial process)

ΔSθtot = 161 – 179000/500 = –197.0, still no good

For T = 1200K (limekiln temperature)

ΔSθtot = 161 – 179000/1200 = +11.8 J mol–1 K–1, definitely feasible, overall positive entropy change

Now assuming ΔSθsys is approximately constant with temperature change and at room temperature the ΔSθsurr term is too negative for ΔSθtot to be plus overall. But, as the temperature is raised, the ΔSθsurr term becomes less negative and eventually at about 800–900oC ΔSθtot becomes plus overall, so the decomposition is now chemically, and 'commercially' feasible in a lime kiln.
You can approach the problem in another more efficient way by solving the total entropy expression for T at the point when the total entropy change is zero. At this point calcium carbonate, calcium oxide and carbon dioxide are at equilibrium.
ΔSθtot–equilib = 0 = 161 – 179000/T, 179000/T = 161, T = 179000/161 = 1112 K

This means that 1112 K is the minimum temperature to get an economic yield. Well at first sight anyway. In fact because the carbon dioxide is swept away in the flue gases so an equilibrium is never truly attained so limestone continues to decompose even at lower temperatures.

8 0
3 years ago
Read 2 more answers
Other questions:
  • What three obstacles did dmitri mendeleev face in his life
    9·2 answers
  • What is the unit of molar mass
    6·1 answer
  • What part of the electromagnetic spectrum that is necessary for the sense of sight in humans?
    15·2 answers
  • Which metalloid has three valence electrons? 1. Lithium 2. boron 3. silicon 4. aluminum 5. arsenic 
    8·2 answers
  • Hexane is a chain organic compound that has the formula C6H14. What type of organic compound is hexane?
    7·2 answers
  • I need help FAST ASAP
    10·1 answer
  • Analyze the graph below and answer the question that follows.
    5·2 answers
  • I need help! Please give me an answer
    7·2 answers
  • What temperature air has low pressure?
    13·1 answer
  • Given that E°red = -0.40 V for Cd2+/Cd at 25°C, find E° and E for the concentration cell expressed using shorthand notation belo
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!