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3 years ago

100 Points Will Make Brainliest. Help Me Please.

Chemistry

2 answers:

Gnoma [55]3 years ago

6 0

Answer:

rubber gloves and glasses

Explanation:

rubber gloves and glasses

Oksana_A [137]3 years ago

3 0

If the glasses and glove were wrong then I would chose the fire extinguisher and the power source should be the correct answer.

That's just what I would do though.

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If the sum of the mass of the reactants is 12.5 what would be the sum of the products be? And explain how you know this

Strike441 [17]

If all the reactants will react and become products, the mass will be 12.5 g. Because the mass of the matter amount will not change during the reaction.

7 0

3 years ago

A wave cycle is

fenix001 [56]

It’s c because a wave cycle is repeating patterns all over again and again

6 0

3 years ago

Carbon and silicon are tetravalent but ge sn pb show di valency. Why

Anuta_ua [19.1K]

<u>Answer:</u>

Carbon and silicon both are tetravalent elements as compared to germanium, tin, and lead which are divalent.

That's because Ge, tin, and Pb show inert pair effect and has a greater nuclear effective charge on the 's' electrons due to poor shielding effect. .That's why these elements are not able to share their valence electrons while carbon and silicon does and show "catenation" which is the ability to form long chain molecules.

4 0

3 years ago

Solutions of sodium carbonate and silver nitrate react to form solid silver carbonate and a solution of sodium nitrate. A soluti

koban [17]

Answer:

1) 2.0 g

2) 0 g

3) 4.17 g

4) 2.57 g

Explanation:

First of all, we need to know the compounds and the reaction. The ion carbonate is $CO3^{-2}$ , and the ion nitrate is $NO3^{-}$ .

Sodium is in group 1, so it must lose one electron to be stable, and be the cation $Na^{+}$ . Silver has only one electron too, so the cation will be $Ag^{+}$ .

To form the chemical compounds, first we put the cation, then the anion, and change their charges without the signal:

Sodium carbonate: Na2CO3

Silver nitrate: AgNO3

Silver carbonate: Ag2CO3

Sodium nitrate: NaNO3

The balanced reaction will be:

Na2CO3 + 2 AgNO3 --> Ag2CO3 + 2 NaNO3

Now, we must check the stoichiometry, which will be 1:2:1:2 (always in number of moles)

The question wants to know the mass value, so we need to know the molar mass of these compounds. Checking the periodic table will see that:

Na = 23 g/mol, C = 12 g/mol, N = 14 g/mol, O = 16 g/mol, Ag = 108 g/mol

So the molar mass of the compounds must be:

Na2CO3 = 106 g/mol (2x23 + 12 + 3x16)

AgNO3 = 170 g/mol (108 + 14 + 3x16)

Ag2CO3 = 276 g/mol (2x108 + 12 + 3x16)

NaNO3 = 85 g/mol

We have a mixture of the reactants, so one probably would be in excess, so, first will need to test. Let's do the stoichiometry calculus using silver nitrate as the limit, so:

1 mol of Na2CO3 ---------- 2 mol of AgNO3

106 g ------------------------------ 2x170 = 340 g

x ------------------------------------ 5.14 g

By a simple direct three rule:

340x = 544.84

x = 1.6 g of Na2CO3

That means that for this reaction, we only need 1.6 g of Na2CO3 to react with 5.14 of AgNO3. How we have 3.60 g of Na2CO3, it is on excess, and all the AgNO3 will be consumed.

1) The mass of Na2CO3 that remains after the reaction will be the initial less the mass that reacted:

m = 3.6 - 1. 6 = 2.0 g

2) All the AgNO3 reacted, so there isn't a mass present after the reaction.

m = 0 g

3) Now, doing the stoichiometry calculus between AgNO3 and Ag2CO3

2 moles of AgNO3 ------------- 1 mol of Ag2CO3

2x170 g ------------------------------- 276 g

5.14 g --------------------------------- x

By a simple direct three rule:

340x = 1418.64

x = 4.17 g of Ag2CO3

4) Now, doing the stoichiometry calculus between AgNO3 and NaNO3

2 moles of AgNO3 ----------------------- 2 moles of NaNO3

2x170 g ---------------------------------------- 2x85 g

5.14 g ------------------------------------------- x

By a simple direct three rule:

340x = 873.8

x = 2.57 g

8 0

3 years ago

Which one of the following is not a valid expression for the rate of the reaction below? 4NH3 + 7O2 → 4NO2 + 6H2O Which one of t

Veseljchak [2.6K]

Answer : All of the above are valid expressions of the reaction rate.

Explanation :

The given rate of reaction is,

$4NH_3+7O_2\rightarrow 4NO_2+6H_2O$

The expression for rate of reaction for the reactant :

$\text{Rate of disappearance of }NH_3=-\frac{1}{4}\times \frac{d[NH_3]}{dt}$

$\text{Rate of disappearance of }O_2=-\frac{1}{7}\times \frac{d[O_2]}{dt}$

The expression for rate of reaction for the product :

$\text{Rate of formation of }NO_2=+\frac{1}{4}\times \frac{d[NO_2]}{dt}$

$\text{Rate of formation of }H_2O=+\frac{1}{6}\times \frac{d[H_2O]}{dt}$

From this we conclude that, all the options are correct.

3 0

3 years ago