Which best describes how isotopes of the same element differ?

Which statement best describes the relationship between observations and conclusions? A. Observations are based on Conclusions B

irga5000 [103]

Answer:

B. Conclusions are based on observations

Explanation:

7 0

2 years ago

How many moles of chromium III nitrate are produced When chromium reacts with 0.85 moles of lead for nitrate to produce chromium

Pepsi [2]

0.85 moles formula units of lead nitrate will produce 0.57 moles formula units of chromium (III) nitrate.

<h3>Explanation</h3>

Typically, the oxidation state of Pb in lead nitrate tend to be +2. In other words, Pb in lead nitrate tends to exist as $\text{Pb}^{2+}$ ions. The formula for a nitrate ion is ${\text{NO}_3}^{-}$ . The charge on each of the nitrate ion is -1. The charge on the two ions should balance. As a result, each $\text{Pb}^{2+}$ ion in lead nitrate would pair up with two ${\text{NO}_3}^{-}$ ions. The formula for lead nitrate will be $\text{Pb}({\text{NO}_3})_2$ . Each formula unit of lead nitrate will contain one $\text{Pb}^{2+}$ ion and two ${\text{NO}_3}^{-}$ ions.

The "III" in the name "chromium (III) nitrate" is a Roman Numeral. It indicates that the oxidation state of Cr in chromium (III) nitrate is +3. The Cr in that compound will exist as $\text{Cr}^{3+}$ . Similarly, each $\text{Cr}^{3+}$ will pair up with three ${\text{NO}_3}^{-}$ ions. The formula for chromium (III) nitrate will be $\text{Cr}(\text{NO}_3})_3$ . Each formula unit of chromium (III) nitrate will contain one ${\text{NO}_3}^{-}$ ion and three ${\text{NO}_3}^{-}$ ions.

0.85 moles formula units of lead nitrate will contain 0.85 × 2 = 1.7 moles of ${\text{NO}_3}^{-}$ ions. Those nitrate ions will end up in 1.7 / 3 = 0.57 moles formula units of chromium (III) nitrate. As a result, the reaction will produce 0.57 moles formula units of chromium (III) nitrate.

7 0

3 years ago

Hypochlorous acid decays in the presence of ultraviolet radiation. Assume that degradation occurs accord- ing to first-order kin

Dennis_Churaev [7]

Answer:

35.75 days

Explanation:

From the given information:

For first-order kinetics, the rate law can be expressed as:

$\mathsf{In \dfrac{C}{C_o} = -kt}$

Given that:

the rate degradation constant = 0.12 / day

current concentration C = 0.05 mg/L

initial concentration C₀ = 3.65 mg/L

$\mathsf{In( \dfrac{0.05}{3.65})= -(0.12) t}$

㏑(0.01369863014) = -(0.12) t

-4.29 = -(0.12)

t = -4.29/-0.12

t = 35.75 days

3 0

2 years ago

Which of these sentences describes a benefit of fracking?

bagirrra123 [75]

Answer is: <span>A. Fracking reduces U.S. dependency on oil and gas from other countries..
Other answers are not bad side of fracking.
</span>Fracking is technique in which rock is fractured by a pressurized liquid and is used in <span>to create cracks in the rock formations through which </span>natural gas<span>, </span>petroleum<span> will flow more freely.</span>

7 0

3 years ago

Read 2 more answers

A chemist wants to examine specific chemical reactions and isolate certain products using a controlled experiment. How would the

professor190 [17]

Answer:

in a laboratory

Explanation:

A controlled experiment refers to the one where everything is an experiment except a single variable is held constant. A collection of information is typically taken as a control group, which is generally the ordinary state, and another group is analyzed( such as chemical reaction as per the question) in which all conditions are similar to the control group except for the variable under examination. The main benefit of a controlled experiment is that confusion over the accuracy of the results can be eliminated more easily.

6 0

2 years ago