Physical Science pre-Test 2020-2021

Chemistry

1 answer:

poizon [28]2 years ago

4 0

Answer:

exothermic I think

Explanation:

IM TWKIGN THE TEST

You might be interested in

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

The two systems that control your body functions are the

KatRina [158]

c) nervous and endocrine system

Hope I helped! ( Smiles )

5 0

3 years ago

How much energy is absorbed in breaking up the water molecules?

tiny-mole [99]

Answer:

1852 kJ/mol

Explanation:

3 0

3 years ago

Usually, it is observed that climates in coastal regions are moderate as compared to climates in the interiors of continents. Wh

Stella [2.4K]

<span>Answer: option D) Conditions over the oceans change slowly because water takes more time than land to gain or lose heat.

This is because water has a high heat capacity meaning that, with the same amount of heat, it will change its temperature less than what substances with lower heat capacities do.
</span>

7 0

3 years ago

Read 2 more answers

Which is the smallest particle into which a compound can be broken down and still remain the same compound? A. atom B. mixture C

Andre45 [30]

The smallest would be a compound

4 0

3 years ago