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3 years ago

1. How many atoms of Li are there in 7.5 moles of Li?

Chemistry

1 answer:

ZanzabumX [31]3 years ago

6 0

Answer: 4.52x10²⁴ atoms Li

Explanation: For 1 mole of Li it is equal to the Avogadro's Number.

Solution:

7.5 moles Li x 6.022x10²³ atoms Li/ 1 mole Li

= 4.52x10²⁴ atoms Li

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BRAINLIESTTTT ASAP!!! PLEASE HELP ME :)

melomori [17]

Answer:

Double replacement

Precipitation reaction

Explanation:

You have the reaction:

REACTANTS PRODUCTS

BaCl₂ (aq) + Na₂SO₄ (aq) ⇒ 2NaCl (aq) + BaSO₄(s)

The general form of a double replacement reaction is the following:

AB + CD ⇒ CD + AB

The reactants basically, exchanged partners. In the case of your problem, Barium(Ba) and Sodium(Na) switched places. So this makes it a double-replacement reaction.

Now how do I know it is a precipitation reaction. A precipitation reaction occurs when two solutions combine and salt is formed. Salt is solid, so how do I know that's what occured? Look at your equation again:

BaCl₂ (aq) + Na₂SO₄ (aq) ⇒ 2NaCl (aq) + BaSO₄(s)

aq means aqueous (liquid)

s means solid

If you look at the product formed in the reaction, from two solutions, it formed a solid. So this is your clue as to why it is a precipitation reaction.

3 0

3 years ago

Phosphine, an extremely poisonous and highly reactive gas, will react with oxygen to form tetraphosphorus decoxide and water, as

erica [24]

<u>Answer:</u> The amount of $P_4O_{10}$ formed is 469.8 grams.

<u>Explanation:</u>

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

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ ......(1)

Given mass of phosphine = 225 g

Molar mass of phosphine = 34 g/mol

Putting values in equation 1, we get:

$\text{Moles of phosphine}=\frac{225g}{34g/mol}=6.62mol$

The given chemical reaction follows:

$4PH_3(g)+8O_2(g)\rightarrow P_4O_{10}(s)+6H_2O(g)$

Assuming that oxygen gas is present in excess, it is considered as an excess reagent.

Phosphine is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

4 moles of phosphine produces 1 mole of $P_4O_{10}$

So, 6.62 moles of phosphine will produce = $\frac{1}{4}\times 6.62=1.655mol$ of $P_4O_{10}$

Now, calculating the mass of $P_4O_{10}$ by using equation 1:

Molar mass of $P_4O_{10}$ = 283.9 g/mol

Moles of $P_4O_{10}$ = 1.655 moles

Putting values in equation 1, we get:

$1.655mol=\frac{\text{Mass of }P_4O_{10}}{283.9g/mol}\\\\\text{Mass of }P_4O_{10}=(1.655mol\times 283.9g/mol)=469.8g$

Hence, the amount of $P_4O_{10}$ formed is 469.8 grams.

8 0

2 years ago

Which of the following compound names is obviously INCORRECT?

Irina18 [472]

The compound which is obviously incorrect is dihydrogen oxide

3 0

3 years ago

7. Describe the difference between a genetically modified organism (GMO) and an unmodified organism.

schepotkina [342]

Answer:

there

Explanation:

organic food is farmed and manufactured per the guidelines put forth by the Department of Agriculture. Organic food is typically pesticide-free, GMO-free, and sustainably farmed.

Non-GMO food, or non-genetically modified food, has not been altered or engineered in any way. Non-GMO food doesn’t necessarily adhere to the same guidelines that organic food does.

GMO food has been genetically modified in some form, usually in a laboratory.

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2 years ago

What is the change in enthalpy associated with the combustion of 530 g of methane (CH4)?Report your answer in scientific notatio

Veseljchak [2.6K]

Answer:

$-3.0\times 10^4 kJ$ is the change in enthalpy associated with the combustion of 530 g of methane.