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Stolb23 [73]
3 years ago
13

In very early human history, complex sanitation systems were not needed because settlements were usually very small, like the vi

llage below. However, as cities became larger and population densities increased, one major advancement was the development of _____ which helped to channel waste waters away from human populations more effectively than in the past
Chemistry
1 answer:
abruzzese [7]3 years ago
3 0

Answer:

Filter??

Explanation:

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WILL GIVE BRAINLEST!!
qwelly [4]
Coastal flooding occurs when normally dry, low-lying land is flooded by seawater.[1] The extent of coastal flooding is a function of the elevation inland flood waters penetrate which is controlled by the topography of the coastal land exposed to flooding.The seawater can flood the land via from several different paths:
3 0
3 years ago
Whats the balanced equation for sodium hydroxide + ammonium sulphate=sodium sulphate + amonia + h2o​
Nady [450]

Answer:

2NaOH + (NH4) 2SO4 = Na2SO4(s) + 2NH3(g) + 2H2O(l)

Two moles of sodium hydroxide reacts with 1 Mike of ammonium sulphate to give 1 mole of Sodium sulphate, 2 moles of ammonia gas and 2 moles of water

Explanation:

7 0
3 years ago
What is the mole ratio of the following equation?
Liono4ka [1.6K]
The mole ratio would be 2:2:2
7 0
2 years ago
When light is shown on a mixture of chlorine and chloromethane, carbon tetrachloride is one of the components of the final react
velikii [3]

A free-radical substitution reaction is likely to be responsible for the observations. The reaction mechanism of a reaction like this can be grouped into three phases:

  • Initiation; the "light" on the mixture deliver sufficient amount of energy such that the halogen molecules undergo homologous fission. It typically takes ultraviolet radiation to initiate fissions of the bonds.  
  • Propagation; free radicals react with molecules to produce new free radicals and molecules.
  • Termination; two free radicals combine and form covalent bonds to produce stable molecules. Note that it is possible for two carbon-containing free-radicals to combine, leading to the production of trace amounts of long carbon chains in the product.

Initiation

\text{Cl}-\text{Cl} \stackrel{\text{UV}}{\to} \text{Cl}\bullet + \bullet\text{Cl}

where the big black dot indicates unpaired electrons attached to the atom.

Propagation

\text{CH}_3\text{Cl}+ \text{Cl}\bullet \to \bullet\text{CH}_2\text{Cl} + \text{HCl}

\bullet\text{CH}_2\text{Cl} + \text{Cl}_2 \to \text{CH}_2\text{Cl}_2 + \text{Cl}\bullet

\text{CH}_2\text{Cl}_2 + \text{Cl}\bullet \to \bullet\text{CHCl}_2 + \text{HCl}

\bullet\text{CHCl}_2+ \text{Cl}_2 \to \text{CHCl}_3 + \bullet \text{Cl}

\text{CHCl}_3 + \text{Cl}\bullet \to \bullet\text{CCl}_3 + \text{HCl}

\bullet\text{CCl}_3 + \text{Cl}_2 \to \text{CCl}_4 + \text{Cl}\bullet

Termination

\text{Cl}\bullet + \bullet\text{Cl} \to \text{Cl}-\text{Cl}

8 0
3 years ago
How many grams of pure naoh must be used to prepare 10.0 l of a solution that has a ph of 13? __________g?
padilas [110]

40 g NaOH. You must use 40 g NaOH to prepare 10.0 L of a solution that has a pH of 13.

<em>Step 1</em>. Calculate the pOH of the solution

pOH = 14.00 – pH = 14.00 -13 = 1

<em>Step 2</em>. Calculate the concentration of NaOH

[NaOH] = [OH^(-)] = 10^(-pOH) mol/L = 10^(-1) mol/L = 0.1 mol/L

<em>Step 3</em>. Calculate the moles of NaOH

Moles of NaOH = 10.0 L solution × (0.1 mol NaOH/1 L solution) = 1 mol NaOH

<em>Step 4</em>. Calculate the mass of NaOH

Mass of NaOH = 1 mol NaOH × (40.00 g NaOH/1 mol NaOH) = 40 g NaOH

8 0
3 years ago
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