All categories

3 years ago

Help please chemistry sucks ;(

Chemistry

1 answer:

ElenaW [278]3 years ago

4 0

3.50g H2:

3.50g H2 x 1 mol H2 / 2(1.01gH2)= 1.7675mol H2
- the grams cancel out
- the answer rounded up would be: 2 mol H2

You might be interested in

When physical properties are measured their identity will be changed. True or False

wolverine [178]

Answer:

False

Explanation:

A physical change is a change to a sample of matter in which some properties of the material change, but the identity of the matter does not.

5 0

3 years ago

Which property of potential energy distinguishes it from kinetic energy?

vazorg [7]

Answer: Shape and position

Explanation:

I just took the test and I got it correct

3 0

3 years ago

6) (a) Calculate the absorbance of the solution if its concentration is 0.0278 M and its molar extinction coefficient is 35.9 L/

Anvisha [2.4K]

Answer:

6) (a) 0.499; (b) 31.7 %

7) 0.15

Explanation:

6) (a) Absorbance

Beer's Law is

$A = \epsilon cl\\A = \text{35.9 L&\cdot$mol$^{-1}$cm$^{-1}$} $\times$ 0.0278 mol$\cdot$L$^{-1} \times $ 0.5 cm = \mathbf{0.499}$

(b) Percent transmission

$A = \log {\left (\dfrac{1}{T}}\right)}\\\\\%T = 100T\\\\T = \dfrac{\%T}{100}\\\\\dfrac{1}{T} = \dfrac{100 }{\%T}\\\\A = \log \left(\dfrac{100 }{\%T} \right ) = 2 - \log \%T\\\\0.499 = 2 - \log \%T\\\\\log \%T = 2 - 0.499 = 1.501\\\\\%T = 10^{1.501} = \mathbf{31.7}$

7) Absorbance

$A = \log \left (\dfrac{I_{0}}{I} \right ) = \log \left (\dfrac{I_{0}}{0.70I_{0}} \right ) = \log \left (\dfrac{1}{0.70} \right ) = -\log(0.70) = \mathbf{0.15}}$

8 0

3 years ago

Mg2OH has how many unique elements? A. 4 B. 2 C. 3 D. 5

frutty [35]

Answer:

Magnesium hydroxide has 3 unique elements.

Explanation:

Long story short, 2 is the balancing compound in structure to make up hydroxide, therefore 1 compound would be left to create Mg(2O)H.

(This is only an opinion of mathematical science to me, I don't have complete understanding of this subject either, good luck.)

5 0

3 years ago

What are some of the positive and negative effects of the use of plastics?

trapecia [35]

Answer:

Positive: Save fuel and reduces greenhouse gas

Negative: Harmful to human and animal health ( underwater animals), Hurts the food chain

Explanation:

I got it from a video. Hopefully it helps you.

4 0

3 years ago