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Ratling [72]
3 years ago
11

A teacher wants to perform a classroom demonstration that illustrates both chemical and physical changes. Which would be the bes

t demonstration that she could use to illustrate both the changes?
Chemistry
1 answer:
Fofino [41]3 years ago
4 0

A bike rusting is an example of a chemical change since rusting is a chemical reaction. New substances are formed from this reaction. On the other hand, other choices given are just physical changes because only the shape or the physical form of the substances are being changed. An example of a physical change is cutting a paper.

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A client who weighs 70 kg is receiving a solution of 0.9% sodium chloride (normal saline) 500 ml with dopamine 800 mg at 5 ml/ho
nordsb [41]

The mcg/kg/minute the client is receiving is 1.904 mcg/kg/min whose weight is 70 kg.

<h3>What does mcg kg mean?</h3>

1 milligram (mg) = 1000 micrograms (mcg) or 0.001 grams (g) 1 g = 1000 mg 1 kilogram (kg) = 1000 g 1 kg = 2.2 pound (lb) 1 liter (L) = 1000 milliliters (mL)

The number of mcg/kg/minute = flow rate × concentration ÷ mass of client

Flow rate = 12 ml/hour = 12 ml/hour × 1 hr/60 min = 0.2 ml/min

Concentration = mass of dopamine/volume

where

mass of dopamine = 800 mg and

volume =  500 ml

Concentration =800 mg/500 ml

= 1.6 mg/ml

= 1.6 mg/ml × 1000 mcg/mg

= 1600 mcg/ml

mass of client = 70 kg

Calculating mcg/kg/minute

So, substituting the variables into the equation, we have

mcg/kg/minute = flow rate × concentration ÷ mass of client

mcg/kg/minute = 0.08 ml/min × 1600 mcg/ml ÷ 70 kg

mcg/kg/minute = 320 mcg/min ÷ 70 kg

mcg/kg/minute = 1.904 mcg/kg/min

Thus, the mcg/kg/minute the client is receiving is 1.904 mcg/kg/min

Learn more about mcg/kg/minute here:

brainly.com/question/4253005

#SPJ1

7 0
1 year ago
Finely ground nickel (II) hydroxide is placed in a beaker of water. It sinks to the bottom of the beaker and remains unchanged.
Luden [163]

Explanation:

Acid-base reaction will give salt and water.

The 2nd option is correct.

6 0
3 years ago
In the reaction MgCl2 + 2KOH Mg(OH)2 + 2KCl, if 3 moles MgCl2 are added to 4 moles KOH, what determines how much Mg(OH)2 is made
LenKa [72]
The correct option is C. The amount of MgCl2. we know this because <span>no matter how much you increase KOH, if you dont increase Mgcl2, the amount of Mg(OH)2 remains the same. Hope this works for you</span>
8 0
3 years ago
Please help! Thanks
trapecia [35]

Th actual yield of the reaction is 24.86 g

We'll begin by calculating the theoretical yield of the reaction.

2Na + Cl₂ → 2NaCl

Molar mass of Na = 23 g/mol

Mass of Na from the balanced equation = 2 × 23 = 46 g

Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol

Mass of NaCl from the balanced = 2 × 58.5 = 117 g

From the balanced equation above,

46 g of Na reacted to produce 117 g of NaCl.

Therefore,

11.5 g of Na will react to produce = (11.5 × 117) / 46 = 29.25 g of NaCl.

Thus, the theoretical yield of NaCl is 29.25 g.

Finally, we shall determine the actual yield of NaCl.

  • Percentage yield = 85%
  • Theoretical yield = 29.25 g
  • Actual yield =?

Actual yield = Percent yield × Theoretical yield

Actual yield = 85% × 29.25

Actual yield = 0.85 × 29.25 g

Actual yield = 24.86 g

Learn more about stoichiometry: brainly.com/question/25899385

7 0
2 years ago
Which material is primarily a mixture of weathered rock and organic matter?
kumpel [21]
2)soil it's soil because soil is made out of <span>weathered rock and organic matter</span>
3 0
3 years ago
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