Answer:
Hi There! I'm new so I hope I get This Right! ^^
Explanation:
double blind test. the control group receives a placebo. Why is a placebo used in a double-blind test? so that the effects on people in two different groups can be compared.
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Answer:
4.4×10² cm³
Explanation:
From the question given above, the following data were obtained:
Diameter (d) = 68.3 mm
Height (h) = 0.120 m
Volume (V) =?
Next, we shall convert the diameter (i.e 68.3 mm) to cm.
This can be obtained as follow:
10 mm = 1 cm
Therefore
68.3 mm = 68.3 mm / 10 mm × 1 cm
68.3 mm = 6.83 cm
Therefore, the diameter 68.3 mm is equivalent 6.83 cm.
Next, we shall convert the height (i.e 0.120 m) to cm. This can be obtained as follow:
1 m = 100 cm
Therefore,
0.120 m = 0.120 m/ 1 m × 100 cm
0.120 m = 12 cm
Therefore, the height 0.120 m is equivalent 12 cm.
Next, we shall determine the radius of the cylinder. This can be obtained as follow:
Radius (r) is simply half of a diameter i.e
Radius (r) = Diameter (d) /2
r = d/2
Diameter (d) = 6.83 cm
Radius (r) =?
r = d/2
r = 6.83/2
r = 3.415 cm
Finally, we shall determine the volume of the cylinder as follow:
Radius (r) = 3.415 cm
Height (h) = 12 cm
Volume (V) =?
Pi (π) = 3.14
V = πr²h
V = 3.14 × (3.415) ² × 12
V = 440 cm³
V = 4.4×10² cm³
Therefore, the volume of the cylinder is 4.4×10² cm³
Because you need to know how/ learn to try new things for (new experiments) and creativity will teach you different ways on how to do it.
An acid is an ionic compound that produces positive hydrogen ions when dissolved in water. Acids taste sour and turn blue litmus paper red. A base is an ionic compound that produces negative hydroxide ions when dissolved in water. Bases taste bitter and turn red litmus paper blue.
Answer:
91.26 g
Explanation:
Given data:
Mass of PF₃ = 180 g
Mass of F₂ required = ?
Solution:
Chemical equation:
P₄ + 6F₂ → 4PF₃
Moles of PF₃:
Number of moles = mass/ molar mass
Number of moles = 180 g/ 88 g/mol
Number of moles = 2.05 mol
Now we will compare the moles of PF₃ with F₂.
PF₃ : F₂
4 : 6
2.05 : 6/4×2.05 = 3.075
Mass of F₂:
Mass of F₂ = moles × molar mass
Mass of F₂ = 3.075 mol × 38 g/mol
Mass of F₂ = 116.85 g
If reaction yield is 78.1%:
116.85 /100 ×78.1 = 91.26 g
