Identify the double displacement reaction.

1 answer:

3 0

A double replacement reaction occurs when the ionic parts of two ionic compounds are exchanged.

Reaction 1 results in a product which is a single compound. No ionic parts are exchanged.

Reaction 3 results in one compound being separated into its elemental parts. No ionic parts are exchanged.

Reaction 4 has two reactants, but Pb is an element and not an ionic compound. No ionic parts are exchanged.

Hence, the answer is Reaction 2. Both NaBr and Ca(OH)2 are ionic compounds. Br - is the anion in NaBr, and (OH)2 is also an anion. Ionic parts are exchanged.

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What is the answer someone help meeee

Varvara68 [4.7K]

Answer:

1) 8n-3

2) 3+(8-n)

3) 3(n-8)

4) 3(n+8)

6 0

3 years ago

In △ABC, AD and BE are the angle bisectors of ∠A and ∠B and DE ║ AB . Find the length of DE if perimeter of ABDE is 30 cm and AB

-BARSIC- [3]

Answer:

DE = 6 cm

Step-by-step explanation:

Let DE = x cm.

Since DE is parallel to AB therefore by the alternate interior angles theorem, m∠BAD = m∠ADE and m∠ABE = m∠DEB ............(1)

As AD is an angle bisector of ∠A, therefore m∠EAD = m∠DAB ; Since BE is an angle bisector of ∠B ⇒ m∠ABE = m∠EBD.

Therefore, from (1) We get , m∠EAD = m∠ADE and m∠EBD = m∠BED.

So, the triangles ADE and EDB are then isosceles with AE = ED and ED = DB.

So AE = DE = DB = x, and since the perimeter of ABDE is 30 cm, then

12 + x + x + x = 30

⇒ 12 + 3x = 30

⇒ x = 6

Hence, the length of DE is 6 cm.

8 0

3 years ago

Read 2 more answers

Nicole used 3/8 of her ribbon to wrap the present. If she used 6 feet of ribbon for the present how much ribbon did Nicole have

lilavasa [31]

You would set up a proportion. 3/8 = 6/x... cross multiply ( 3*x = 3x and 6*8 = 48) 3x = 48... divide both sides by 3 (3x/3 = x and 48/3 = 16)

So, she originally had 16 feet of ribbon.

6 0

4 years ago

4x−4y=-2 and −9x−4y =-3 solve by adding please !!!

jeyben [28]

1. Add 4x back into -2, you now have -4y=-4x-2. Add +4 from y and now you are at y=-4x+2 and this is the answer!

2. Add -9x back into -3, you now have -4y=9x-3. Add +4 from y and now you are at y=9x-7 and this is your answer!!

I hope this helped! Brainliest? :) -Raven❤️

7 0

3 years ago

What two numbers add to 9 and multiply to -70

Alborosie

X, y - the numbers

The numbers add to 9 and multiply to -70.
$x+y=9 \\
xy=-70 \\ \\
y=9-x \\
xy=-70 \\ \\
\hbox{substitute 9-x for y in the second equation:} \\
x(9-x)=-70 \\
9x-x^2=-70 \\
-x^2+9x+70=0 \\
-x^2+14x-5x+70=0 \\
-x(x-14)-5(x-14)=0 \\
(-x-5)(x-14)=0 \\
-x-5=0 \ \lor \ x-14=0 \\
x=-5 \ \lor \ x=14 \\ \\
y=9-x \\
y=9-(-5) \ \lor \ y=9-14 \\
y=14 \ \lor \ y=-5 \\ \\
(x,y)=(-5,14) \hbox{ or } (x,y)=(14,-5)$

The numbers are -5 and 14.

4 0

3 years ago