. Using improved chemistry equipment in the late 1700s, chemists

How many moles of helium are needed to fill a balloon to a volume of 6.3 L at 28 °C and 320

Ray Of Light [21]

Answer:

.11 mol

Explanation:

Convert mmHg to atms by dividing by 760. Then multiply 6.3 by the atms and divide by .08206*(273+28) to get mol

5 0

2 years ago

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calculate the ph for each case in the titration of 50.0 ml of 0.130 m hclo(aq) with 0.130 m koh(aq). use the ionization constant

-BARSIC- [3]

The ph before the addition of any Koh is 10.105.

Concentration is the abundance of a constituent divided by way of the overall volume of an aggregate. several sorts of mathematical descriptions may be outstanding: mass concentration, molar concentration, variety concentration, and extent awareness.

After the addition of 50 ml KOH,

moles of KOH = 50 * 0.13 = 6.5 mmol

moles of HClO = 50 * 0.13 = 6.5 mmol

occurred hydrolysis solution,

pH = 0.5(14 + pKa + log [base conjugate])

pH = 0.5(14 + (- log (4 * 10^-8)) + log (6.5/(50 + 50)))

pH = 10.105

The concentration of a substance is the quantity of solute found in a given amount of solution. Concentrations are normally expressed in terms of molarity, defined because of the variety of moles of solute in 1 L of answer.

The Concentration of an answer is a measure of the quantity of solute that has been dissolved in a given amount of solvent or answer. A concentrated answer is one that has a rather huge quantity of dissolved solute.

Learn more about concentration here:-brainly.com/question/26255204

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4 0

1 year ago

A pycnometer is a precisely weighted vessel that is used for highly accurate density determinations. Suppose that a pycnometer h

dexar [7]

Answer:

5.758 is the density of the metal ingot in grams per cubic centimeter.

Explanation:

1) Mass of pycnometer = M = 27.60 g

Mass of pycnometer with water ,m= 45.65 g

Density of water at 20 °C = d = $998.2 kg/m^3$

1 kg = 1000 g

$1 m^3=10^6 cm^3$

$998.2 kg/m^3=\frac{998.2 \times 1000 g}{10^6 cm^3}=0.9982 g/cm^3$

Mass of water ,m'= m - M = 45.65 g - 27.60 g =18.05 g

Volume of pycnometer = Volume of water present in it = V

$Density=\frac{Mass}{Volume}$

$V=\frac{m'}{d}=\frac{18.05 g}{0.9982 g/cm^3}=18.08 cm^3$

2) Mass of metal , water and pycnometer = 56.83 g

Mass of metal,M' = 9.5 g

Mass of water when metal and water are together ,m''= 56.83 g - M'- M

56.83 g - 9.5 g - 27.60 g = 19.7 g

Volume of water when metal and water are together = v

$v=\frac{m''}{d}=\frac{19.7 g}{0.9982 g/cm^3}=19.73 cm^3$

Density of metal = d'

Volume of metal = v' = $\frac{M'}{d'}$

Difference in volume will give volume of metal ingot.

v' = v - V

$v'=19.73 cm^3-18.08 cm^3=$

$v'=1.65 cm^3$

Since volume cannot be in negative .

Density of the metal =d'

= $d'=\frac{M'}{v'}=\frac{9.5 g}{1.65 cm^3}=5.758 g/cm^3$

5 0

2 years ago

How long is 5 half lives if the half life is 2.6 hours? Remember to round to the correct number of significant figures and use u

Dmitry [639]

Answer:

$\Delta t = 13\,h$

Explanation:

Half time is period required to desintegrating the half of the initial number of atoms. Then, the total time is:

$\Delta t = 5\cdot (2.6\,h)$

$\Delta t = 13\,h$

3 0

2 years ago

This type of pure substance contains more than one type of element chemically bonded

Alex787 [66]

Answer:

A. Compounds

Explanation:

Firstly, don't let the word "pure" confuse you; this is pretty much irrelevant to the question.

The key to answering this question lies in "substance" and "more than one type of element chemically bonded."

Something you ought to memorize is that a substance is either an element or compound. Therefore, you can eliminate choices B./C.

Next, use the part of the definition that says "more than one type of element chemically bonded" to conclude that it's a compound. Not only is this the definition of a compound, but the fact that is says more than one type of element should automatically tell you that it is different from just a regular element (Choice D.).

6 0

3 years ago