YALL I NEED HELP ASAP

How might it benefit forensic scientists to smaller subcategories for fingerprints?

Inga [223]

Answer: Once the fingerprints are captured and described, judicial physicists use a categorization structure to label the ruling class. The three elementary mark on finger patterns is Whorl, Arch, and Loop. There are more intricate categorization methods that further decay the pattern to plain arches or make camp arches. Loops grant permission be branching or ulnar.

4 0

2 years ago

ou will prepare 250-mL of this solution using a 30% (m/v) NaOH stock solution. How many mL of the NaOH stock solution will you n

ArbitrLikvidat [17]

Answer:

$\boxed{\text{3.3 mL}}$

Explanation:

You must convert 30 % (m/v) to a molar concentration.

Assume 1 L of solution.

1. Mass of NaOH

$\text{Mass of NaOH} = \text{1000 mL solution } \times \dfrac{\text{30 g NaOH}}{\text{100 mL solution}} = \text{300 g NaOH}$

2. Moles of NaOH

$\text{Moles of NaOH} = \text{300 g NaOH} \times \dfrac{\text{1 mol NaOH}}{\text{40.00 g NaOH}} = \text{7.50 mol NaOH}$

3. Molar concentration of NaOH

$c= \dfrac{\text{moles}}{\text{litres}} = \dfrac{\text{7.50 mol}}{\text{1 L}} = \text{7.50 mol/L}$

4. Volume of NaOH

Now that you know the concentration, you can use the dilution formula .

$c_{1}V_{1} = c_{2}V_{2}$

to calculate the volume of stock solution.

Data:

c₁ = 7.50 mol·L⁻¹; V₁ = ?

c₂ = 0.1 mol·L⁻¹; V₂ = 250 mL

Calculations:

(a) Convert millilitres to litres

$V = \text{250 mL} \times \dfrac{ \text{1 L}}{\text{1000 mL}} = \text{0.250 L}$

(b) Calculate the volume of dilute solution

$\begin{array}{rcl}7.50V_{1} & = & 0.1 \times 0.250\\7.50V_{1} &= & 0.0250\\V_{1} & = & \text{0.0033 L}\\& = & \textbf{3.3 mL}\\\end{array}$

$\text{You will need $\boxed{\textbf{3.3 mL}}$ of the stock solution.}$

4 0

3 years ago

What are the two chemical reactions that are responsible for making cooked food so tasty?

KengaRu [80]

Nose what .,...,).),),,

8 0

2 years ago

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I need help with part B . please

myrzilka [38]

So it's good to map out what you know you have and work from there:
We have two liter measurements and one mole measurement, and we need to find the moles.

For this problem, think of it this way: 46 liters of gas = 1.4 moles.
If one side changes, the other has to as well (if the liters decrease, the moles decrease. if the liters increase, so do the moles.) What you can do is put this into a fraction:

 1.4 moles
 46 L 

if we know that each liter of gas is equal to x amount of moles, we know that 11.5 liters equals some amount of moles. You can put this into a fraction too, and make it equal to the other fraction:

1.4 moles = x moles
46 L 11.5 L

Then get your calculator out and do some algebra.

11.5 * (1.4/46) = x

The answer should come out to be: 0.35 moles

8 0

3 years ago

Frozen ice caps in the Arctic Ocean are composed of?

rjkz [21]

Answer

D a mixture of salt and fresh water

4 0

3 years ago

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