Question about Scientific Explorer My First Chemistry Kit

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I am going to assume your term, "nf," which I do not recognize as an acceptable unit of the metric system, is meant to be **molarity** **(M)**. So, it seems to me that you are asking for the __molarity__ of the solution that is indicated in the problem.

To calculate the molarity of the solution of NaOH in this problem, one must apply the ratio, moles per liter of solution, the definition of molarity (moles/L).

A 27.5% solution means (27.5 grams) / (100 grams of solution), which in this case is equivalent to

27.5 g / 100 mL solution, because the density of water is 1.00 g/mL.

Since 100 g solution is specified, that means there are 27.5 g of NaOH in the solution (100 mL volume, or 0.100 L).

Moles of NaOH in solution = [27.5 g NaOH / 40.0 g mol NaOH/ mol NaOH] = 0.688 mol NaOH.

__Therefore, molarity of NaOH = mol NaOH / L = (0.688 mol NaOH / 0.100 L)__ = **6.88 M NaOH**.

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Posted on Jan 11, 2011

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Posted on Jan 02, 2017

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1/2 cup

Here is how volume/weight conversions work. A gram is a unit of weight. A cup is a unit of volume. Volume is the amount of space an ingredient occupies and weight is the mass or "heaviness" of an ingredient.

500 grams of mini marshmallows = 10 cups

500 grams of flour = 4 cups

500 grams of sugar = 2.5 cups

As you can see, the weight for these ingredients are the same, yet the volumes are different. This is because each ingredient has a different density.

Here is another example:

A cup of feathers and a cup of lead pellets both occupy 8 fluid ounces of volume. The feathers will weigh a lot less than 8 ounces on a scale and the lead will weigh a lot more than 8 ounces on a scale.

Asking how many cups equal 100 grams would be the same as asking how many hours are in a 100 inches. Volume and weight are two completely different measurement systems... just as time and length are two different measurement systems. The only difference is that volume and weight can be linked through density.... mathematically speaking. Density = Mass divided by Volume. Density can change for the same ingredient. For example, a cup of sifted flour will weigh a lot less than a cup of unsifted flour. A pint of water will vary in weight depending on the temperature of the water.

There are websites that do volume/weight conversions based on density. Two great websites are:

http://www.onlineconversion.com and

http://www.gourmetsleuth.com or, you can look in a cookbook that has a volume/weight equivalency chart.

Here is how volume/weight conversions work. A gram is a unit of weight. A cup is a unit of volume. Volume is the amount of space an ingredient occupies and weight is the mass or "heaviness" of an ingredient.

500 grams of mini marshmallows = 10 cups

500 grams of flour = 4 cups

500 grams of sugar = 2.5 cups

As you can see, the weight for these ingredients are the same, yet the volumes are different. This is because each ingredient has a different density.

Here is another example:

A cup of feathers and a cup of lead pellets both occupy 8 fluid ounces of volume. The feathers will weigh a lot less than 8 ounces on a scale and the lead will weigh a lot more than 8 ounces on a scale.

Asking how many cups equal 100 grams would be the same as asking how many hours are in a 100 inches. Volume and weight are two completely different measurement systems... just as time and length are two different measurement systems. The only difference is that volume and weight can be linked through density.... mathematically speaking. Density = Mass divided by Volume. Density can change for the same ingredient. For example, a cup of sifted flour will weigh a lot less than a cup of unsifted flour. A pint of water will vary in weight depending on the temperature of the water.

There are websites that do volume/weight conversions based on density. Two great websites are:

http://www.onlineconversion.com and

http://www.gourmetsleuth.com or, you can look in a cookbook that has a volume/weight equivalency chart.

Apr 15, 2015 | Home

http://calculatorsoup.com/calculators/conversions/weight.php

Feb 24, 2015 | Kitchen Appliances - Others

nf =not filling , not enough water to machine

Sep 11, 2014 | Maytag Neptune MAH5500B Front Load Washer

The total mass is the sum of the masses of the individual pails

Total mass =18.49*2 kg =36.98 kg

Total mass =18.49*2 kg =36.98 kg

Aug 21, 2014 | Office Equipment & Supplies

108 grams.

If this is homework, be sure to show your work.

If this is homework, be sure to show your work.

Jan 23, 2014 | Office Equipment & Supplies

The equivalent of the EE or EXP button on the Casio Fx-115ES is marked
as x10^X. It is located at the bottom right of the key pad left of the =
key.

To enter the power of 10 in a number written in scientific notation, you press the x10^X button followed by the exponent. If the exponent is negative you press the change sign key first [(-)] , then the one or 2 digits in the exponent.

Example Enter the mass of the proton m_p in kilograms

**1.6726217 [x10^X] [(-)]27 [=] **

In grams the value above is multiplied by 1000.

or**1.6726217 [x10^X] [(-)]24 [=] **

Since the calculator has the physical constants (the FX-991ES definititely has them)

To enter the power of 10 in a number written in scientific notation, you press the x10^X button followed by the exponent. If the exponent is negative you press the change sign key first [(-)] , then the one or 2 digits in the exponent.

Example Enter the mass of the proton m_p in kilograms

In grams the value above is multiplied by 1000.

or

Since the calculator has the physical constants (the FX-991ES definititely has them)

- Display the proton mass in kilograms
- [SHIFT ][7] to open the constants catalog,
- type 01 for the proton mass, then press the [x^-1].
- Divide the result by 1000
- You should get 5.978638635 x10^23

Feb 07, 2012 | Casio FX-115ES Scientific Calculator

The equivalent od the EE or EXP button on the Casio Fx-115ES is marked as x10^X. It is located at the bottom right of the key pad left of the = key.

To enter the power of 10 in a number written in scientific notation, you press the x10^X button followed by the exponent. If the exponent is negative you press the change sign key first [(-)] , then the one or 2 digits in the exponent.

Example Enter the mass of the proton m_p in kilograms

**1.6726217 [x10^X] [(-)]27 [=]**

To enter the power of 10 in a number written in scientific notation, you press the x10^X button followed by the exponent. If the exponent is negative you press the change sign key first [(-)] , then the one or 2 digits in the exponent.

Example Enter the mass of the proton m_p in kilograms

Feb 07, 2012 | Casio FX-115ES Scientific Calculator

1 Look up the formula for the aluminum acetate.

2 Count the number of Hydrogen atoms per molecule: Call that nH.

3 Dividing 2.24*10^22 by nH you get the number of molecules of acetate.

4. Divide that number by Avogadro's Number to obtain the number of moles required.

5. Multiply the number of moles by the molecular mass of the aluminum acetate (look it up or use the periodic table to calculate it), you will get the mass of aluminum acetate that contains 2.24*10^22 hydrogen atoms.

2 Count the number of Hydrogen atoms per molecule: Call that nH.

3 Dividing 2.24*10^22 by nH you get the number of molecules of acetate.

4. Divide that number by Avogadro's Number to obtain the number of moles required.

5. Multiply the number of moles by the molecular mass of the aluminum acetate (look it up or use the periodic table to calculate it), you will get the mass of aluminum acetate that contains 2.24*10^22 hydrogen atoms.

Sep 14, 2011 | Texas Instruments TI-84 Plus Calculator

0.8915x1.6605=1.480335750

Multiplying this by 10^-27 gives 1.480335750x10^-27.

In your result you left out the 10 maybe because your calculator does not display it.

Multiplying this by 10^-27 gives 1.480335750x10^-27.

In your result you left out the 10 maybe because your calculator does not display it.

Dec 14, 2010 | Casio FX-115ES Scientific Calculator

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