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2 years ago

Which statement best describes a difference between electromagnetic waves

Chemistry

2 answers:

9966 [12]2 years ago

6 0

Answer:

Explanation:

electronic waves transmits energy but mechanical waves require a medium in order to transport their energy from bgg one place to another.

Gekata [30.6K]2 years ago

6 0

Answer:

it is B.) Electromagnetic waves vibrate in two directions that are

Explanation:

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2nd part of the other one plz help

Natalija [7]

18. Reaction will occur.

19. Reaction Will occur.

20. Reaction will occur.

21. Reaction will occur.

22. Reaction won't occur.

23. Reaction will occur.

24. Reaction will occur.

25. Reaction won't occur.

<h3><u>Explanation</u>:</h3>

The reaction rate of the metals with water, steam, acid, or hydroxides or their inert behavior towards them are noted in the metal activity series.

It contains all the metals one after the other which and the upper metal can replace the lower metal from its salt.

Calcium can replace hydrogen from acid, so the reaction will occur in 18. The products formed are calcium phosphate and hydrogen gas.

Chlorine is more reactive than bromine. So it can replace bromine from its salt to from bromine gas and magnesium chloride.

Aluminium can replace iron from its salt. So it will form aluminium oxide and iron metal. This reaction is used to obtain iron from ores.

Zinc can replace hydrogen from acid. So the products will be zinc chloride and hydrogen gas.

Chromium cannot displace hydrogen form water. So the reaction won't occur.

Tin can replace hydrogen form acid. So the reaction will proceed.

Magnesium will replace platinum from its salt. So magnesium oxide and platinum will form.

Bismuth cannot replace hydrogen from acid. So the reaction won't proceed.

4 0

3 years ago

Which prefix indicates a molecule with 2 carbon atoms?

aleksandrvk [35]

The answer is A. Eth-

7 0

3 years ago

Lead can be prepared from galena [lead(II) sulfide] by first roasting the galena in oxygen gas to form lead(II) oxide and sulfur

Vesna [10]

Answer:

a) Step 1:

$2PbS(g)+3O_2(g)\overset{roasting}\rightarrow 2PbO(s)+2SO_2(g)$

Step 2:

$2PbO(s)+PbS(s)\overset{\Delta }\rightarrow 3Pb(l)+SO_2(g)$

b) The overall balanced reaction for given process is ;

$3PbS(s)+3O_2(g)\rightarrow 3Pb(l)+3SO_2(g)$

Explanation:

Galena = $PbS$

Lead(II) oxide = $PbO$

Sulfur dioxide = $SO_2$

Step 1:

Roasting the galena in oxygen gas to form lead(II) oxide and sulfur dioxide.

Balanced equation of step 1:

$2PbS(g)+3O_2(g)\overset{roasting}\rightarrow 2PbO(s)+2SO_2(g)$ ..[1]

Step 2:

Heating the metal oxide with more galena forms the molten metal and more sulfur dioxide.

Balanced equation of step 2:

$2PbO(s)+PbS(s)\overset{\Delta }\rightarrow 3Pb(l)+SO_2(g)$ ..[2]

For over all reaction add [1] and [2]. The overall balanced reaction for given process is ;

$3PbS(s)+3O_2(g)\rightarrow 3Pb(l)+3SO_2(g)$

5 0

3 years ago

Read 2 more answers

A chemical substance that increases the reaction rate and lowers the activation energy needed to start a reaction is

Elza [17]

A catalyst lowers the activation energy needed to start a reaction

4 0

3 years ago

Read 2 more answers

Which one of the following will change the value of anequilibrium constant?

IRINA_888 [86]

Answer:

d. changing temperature

Explanation:

The thermodynamic equilibrium constant K is defined as a quantity characterizing the equilibrium of a chemical reaction. For a reaction where concentrations are in equilibrium:

aA + bB ⇄ cC + dD

The equilibrium constant is:

$k = \frac{[C]^c[D]^d}{[A]^a[B]^b}$

Thus, the equilibrium constant will change if:

a. Varying the initial concentration of reactants . FALSE. The k constant doesn't depend of initial concentrations but concentration in equilibrium does.

b. Adding other substances that do not react with any of thespecies involved in the equilibrium . FALSE. The equilibrium constant just depends of substances that are involved in the equilibrium

c. Varying the initial concentration of products . FALSE. Again, equilibrium constant doesn't depend of initial concentrations.

d. Changing temperature . <em>TRUE. </em>As a thermodynamic constant, k depends of temperature thus:

$K = e^(-dG/RT)$

e. Changing the volume of the reaction vessel. FALSE. The changing in the volume of the reaction vessel will change just the initial concentrations of the reactants.

I hope it helps!

6 0

2 years ago