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frutty [35]
3 years ago
14

What does it mean when science is a black box?

Chemistry
1 answer:
SashulF [63]3 years ago
4 0
<span>In science, computing, and engineering, a black box is a device, system or object which can be viewed in terms of its inputs and outputs without any knowledge of its internal workings. Its implementation is "opaque" (black)</span>
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Chapter 7 Chemistry #52-71
Sophie [7]

If you want more instant and correct answers from people in brainly in the future please provide more information to the question you ask please and thank you. -Rogue

6 0
4 years ago
Amphetamine (c9h13n) is a weak base with a pkb of 4.2. calculate the ph of a solution containing an amphetamine concentration of
soldier1979 [14.2K]

Answer:

pH = 10.505

Explanation:

Molar mass of Amphetamine ( C9H13N) = 135 g/mol

Given that the concentration of Amphetamine = 225 mg/L

mass of Amphetamine in one Liter = \frac{225}{ 1000} = 0.225 g

Number of moles of Amphetamine in one liter =\frac {0.225 g} { 135g/mol}

= 0.001667 mol

∴ molarity = 0.0017 M

              C₉H₁₃N          +        H₂O -------->       C₉H₁₃NH⁺  +      OH⁻

I(M)         0.001667   M                                                  0                 0

C(M)            -x                                                                  x                 x

E(M)         0.001667 - x                                                   x                 x

Pkb = -log Kb = 4.2

∴ Kb = 6.309 x 10⁻⁵

Kb = 6.309 x 10⁻⁵

Equilibrium constant  = [C₉H₁₃NH⁺][OH⁻]/ [C₉H₁₃N]

6.309 x 10⁻⁵  = x² / 0.001667-x

where 0.001667 -x ≅ 0.001667

Then;

x² = 6.309 x 10⁻⁵  × 0.001667

x² =  1.0517103 × 10⁻⁷

x = \sqrt {1.0517103 * 10^{-7}

x = 0.00032 M

x = [OH-] = 0.00032 M

∴ pOH = -log [OH-]

pOH = -log (0.00032)

pOH =3.495

pH = 14 - 3.495

= 10.505

4 0
4 years ago
The law of definite proportions states that______.
Gwar [14]

Answer:

Law of definite proportions, statement that every chemical compound contains fixed and constant proportions (by mass) of its constituent elements.

5 0
3 years ago
How many particles are in 3.4 moles of HCl?
Lady_Fox [76]

Answer:

The volume is 77 L.

Explanation:

where P is pressure, V is volume, n is moles, R is the gas constant, and T is temperature in Kelvins.

The current STP temperature is 0∘C or 273.15 K (used for gas laws), and the pressure is 105Pa, which most people write as 100 kPa (both pressures are equal).

7 0
3 years ago
Maia says that both lines on this position vs time graph show acceleration. Is she correct? Why or why not? help me please i nee
Margarita [4]
Let's start by using the definition of acceleration. Acceleration is defined as the change in velocity over the change in time. In equation, that would be Δvelocity/Δtime. Based on the axes of the given graph, it shows the trend of position over time. So, the slope of the line and the curve shows the change of position over change of time, Δdistance/Δtime. In physics, this is the definition of speed or velocity. So, Maia is incorrect. Both curves show the speed or velocity of the object, and not acceleration. If the graph used a y-axis of velocity instead of position, then only at that instance, would be Maia be correct.

The difference between the two is, the straight line shows constant velocity while the curve line shows changing velocity. 

7 0
3 years ago
Read 2 more answers
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