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2 years ago

Why do we have rain........................

Chemistry

1 answer:

VladimirAG [237]2 years ago

6 0

Answer:

to watered our source of food

the "PLANTS & TREES"

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What characteristics does the serval have that make it well-suited to life on the savanna ?

nika2105 [10]

It is very camouflaged this way it will survive longer then most other animals

5 0

3 years ago

Read 2 more answers

What is the chemical combination of calcium cloride and aluminum

nexus9112 [7]

Answer:

Calcium chloride react with aluminum to produce calcium and aluminum chloride. This reaction takes place at a temperature of 600-700°C.

CaCl2+F2 -> CaF2 + Cl2

7 0

3 years ago

Find the pH. What are the pH values for the following solutions? (a) 0.1 M HCl (b) 0.1 M NaOH (c) 0.05 M HCl (d) 0.05 M NaOH

slega [8]

Answer:

(a) $pH=1$

(b) $pH=1.3$

(d) $pH=12.7$

Explanation:

Hello,

In this case, we define the pH in terms of the concentration of hydronium ions as:

$pH=-log([H^+])$

Which is directly computed for the strong hydrochloric acid (consider a complete dissociation which means the concentration of hydronium equals the concentration of acid) in (a) and (c) as shown below:

(a)

$[H^+]=[HCl]=0.1M$

$pH=-log(0.1)=1$

(b)

$[H^+]=[HCl]=0.05M$

$pH=-log(0.05)=1.3$

Nevertheless, for the strong sodium hydroxide, we don't directly compute the pH but the pOH since the concentration of base equals the concentration hydroxyl in the solution:

$[OH^-]=[NaOH]$

$pOH=-log([OH^-])$

$pH=14-pOH$

Thus, we have:

(b)

$pOH=-log(0.1)=1\\pH=14-1=13$

(d)

$pOH=-log(0.05)=1.3\\pH=14-1.3=12.7$

Best regards.

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3 years ago

Fine the volume in dm³ and in Ml of a 0.505 mol/dm of NaCH required to react with 40Ml of 0.505 molar concentration of H2SO4

dedylja [7]

watch u know bout rolling down in the deep...

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3 years ago

Modern pennies are composed of zinc coated with copper. A student determines the mass of a penny to be 2.483 g and then makes se

Aleonysh [2.5K]

Answer:

97.1%

Explanation:

Using the ideal gas equation, the number of moles of hydrogen gas produced can be calculated from information provided about the volume of gas evolved at a given temperature and pressure.

The stoichiometry of the reaction is now used to obtain the number of moles of Zn that will produce a given number of moles of hydrogen from the balanced reaction equation as shown. This gives us the number of moles of zinc reacted hence the mass of zinc in the coin since it is assumed that all the zinc reacts.

This is now used to calculate the mass percentage of Zn as shown.

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3 years ago