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.
Answer:
C.
Step-by-step explanation:
Since 40% of the students prefer chocolate ice cream, 60% don't prefer chocolate ice cream. Use this proportion set equal to 25 to find the number of students who prefer vanilla ice cream, instead of chocolate ice cream.
Answer:
407.22 foot is the boat from the base of the lighthouse
Step-by-step explanation:
Given the statement: An observer on top of a 50-foot tall lighthouse sees a boat at a 7° angle of depression.
Let x foot be the distance of the object(boat) from the base of the lighthouse
Angle of depression =
[Alternate angle]
In triangle CAB:
To find AB = x foot.
Using tangent ratio:
Here, BC = 50 foot and
then;
or
Simplify:
AB = x = 407.217321 foot
Therefore, the boat from the base of the light house is, 407.22'
Multiplying by 2, the next one would be 160
Answer:
y=2x+7
Step-by-step explanation:
y-y1=m(x-x1)
y-9=2(x-1)
y=2x-2+9
y=2x+7