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3 years ago

What do a prism, a magnifying glass, a microscope, and eyeglasses ALL have in common?

Chemistry

2 answers:

quester [9]3 years ago

6 0

Lense .......................

Viefleur [7K]3 years ago

4 0

They all can condense and manipulate light

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Enter your answer in the provided box. A person's blood alcohol (C2H5OH) level can be determined by titrating a sample of blood

Annette [7]

Answer: The mass percent of alcohol in blood is 0.183 %

Explanation:

To calculate the moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Molarity of $Cr_2O_7^{2-}$ solution = 0.05961 M

Volume of solution = 35.46 mL = 0.03546 L (Conversion factor: 1 L = 1000 mL)

Putting values in above equation, we get:

$0.05961M=\frac{\text{Moles of }Cr_2O_7^{2-}}{0.03546L}\\\\\text{Moles of }Cr_2O_7^{2-}=(0.05961mol/L\times 0.03546L)=2.11\times 10^{-3}mol$

The given chemical reaction follows:

$16H^+(aq.)+2Cr_2O_7^{2-}(aq.)+C_2H_5OH(aq.)\rightarrow 4Cr^{3+}(aq.)+2CO_2(g)+11H_2O(l)$

By Stoichiometry of the reaction:

2 moles of dichromate ions react with 1 mole of ethanol.

So, $2.11\times 10^{-3}mol$ of dichromate ions will react with = $\frac{1}{2}\times 2.11\times 10^{-3}=1.06\times 10^{-3}mol$

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Moles of ethanol = $1.06\times 10^{-3}mol$

Molar mass of ethanol = 46.07 g/mol

Putting values in above equation, we get:

$1.06\times 10^{-3}mol=\frac{\text{Mass of ethanol}}{46.07g/mol}\\\\\text{Mass of ethanol}=(1.06\times 10^{-3}mol\times 46.07g/mol)=0.0488g$

To calculate the mass percent of ethanol in blood, we use the equation:

$\text{Mass percent of ethanol}=\frac{\text{Mass of ethanol}}{\text{Mass of blood plasma}}\times 100$

Mass of blood plasma = 26.60 g

Mass of ethanol = 0.0488 g

Putting values in above equation, we get:

$\text{Mass percent of ethanol}=\frac{0.0488g}{26.60g}\times 100=0.183\%$

Hence, the mass percent of alcohol in blood is 0.183 %

5 0

3 years ago

Which of these statements about reaction rates is accurate? All chemical reactions occur at the same rate. All chemical reaction

Nadya [2.5K]

Answer:

The correct answer is "All chemical reactions occur at different rates".

Explanation:

The reaction speed is given by the amount of substance that is transformed into a given reaction per unit volume and time. Several factors influence the speed of a chemical reaction. One of them is the concentration of the reagents and the other the temperature, as well as the pressure.

Have a nice day!

5 0

3 years ago

Read 2 more answers

(a) Calculate the density of a 374.5-g sample of copper if it has a volume of 41.8 cm3. (b) A student needs 15.0 g of ethanol fo

o-na [289]

Answer:

For a: The density of the sample of copper is $8.96g/cm^3$

For b: The volume of ethanol needed is 19.0 mL

For c: The mass of mercury is 340. grams

Explanation:

To calculate density of a substance, we use the equation:

$\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}$ ......(1)

For a:

Mass of copper = 374.5 g

Volume of copper = $41.8cm^3$

Putting values in equation 1, we get:

$\text{Density of copper}=\frac{374.5g}{41.8cm^3}\\\\\text{Density of copper}=8.96g/cm^3$

Hence, the density of the sample of copper is $8.96g/cm^3$

For b:

Mass of ethanol = 15.0 g

Density of ethanol = 0.789 g/mL

Putting values in equation 1, we get:

$0.789g/mL=\frac{15.0g}{\text{Volume of ethanol}}\\\\\text{Volume of ethanol}=\frac{15.0g}{0.789g/mL}=19.0mL$

Hence, the volume of ethanol needed is 19.0 mL

For c:

Volume of mercury = 25.0 mL

Density of mercury = 13.6 g/mL

Putting values in equation 1, we get:

$13.6g/mL=\frac{\text{Mass of mercury}}{25.0mL}\\\\\text{Mass of mercury}=(13.6g/mL\times 25.0mL)=340.g$

Hence, the mass of mercury is 340. grams

5 0

3 years ago

Metric conversion 125 mg = _______kg

Romashka [77]

0.000125

Explanation:

if you remember King Henry Died Drinking Chocolate Milk= K H D & D C M

find what your converting to and move the decimal that many times in that direction.

3 0

3 years ago

Read 2 more answers

How do I determine the number of a particle in a compound?

Vika [28.1K]

Answer:

The mathematical equation, N = n × NA, can be used to find the number of atoms, ions or molecules in any amount (in moles) of atoms, ions or molecules: 10 moles of helium atoms = 10 × (6.022 × 1023) = 6.022 × 1024 helium atoms.

Explanation:

6 0

3 years ago