What is the molar mass of Na2Cr2O7?

A 0.500-g sample of chromium metal reacted with sulfur powder to give 0.963 g of product. Calculate the empirical formula of the

IgorC [24]

Answer: The empirical formula for the given compound is $Cr_2S_3$

Explanation : Given,

Mass of product = 0.963 g

Mass of Cr = 0.500 g

Mass of S = 0.963 g - 0.500 g = 0.463 g

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Cr = $\frac{\text{Given mass of Cr}}{\text{Molar mass of Cr}}=\frac{0.500g}{52g/mole}=0.00962moles$

Moles of S = $\frac{\text{Given mass of S}}{\text{Molar mass of S}}=\frac{0.463g}{32g/mole}=0.0145moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.00962 moles.

For Cr = $\frac{0.00962}{0.00962}=1$

For S = $\frac{0.0145}{0.00962}=1.5$

To make in a whole number we are multiplying the ratio by 2, we get:

The ratio of Cr : S = 1 : 1.5

The ratio of Cr : S = 2 : 3

Step 3: Taking the mole ratio as their subscripts.

The ratio of Cr : S = 2 : 3

Hence, the empirical formula for the given compound is $Cr_2S_3$

8 0

4 years ago

1. What volume is required to contain 100.0 mol O2 at STP?

Colt1911 [192]

Answer:

The volume is 2238,6 L

Explanation:

We use the formula PV=nRT. The conditions STP are: 1 atm of pressure and 273K of temperature:

PV=nRT ---> V=(nRT)/P

V= 100 mol x 0,082 l atm/K mol x 273K/ 1 atm

V=2238, 6L

5 0

3 years ago

Which metal is more active than NI and less active than Zn?

Mademuasel [1]

Answer : The correct option is, (2) Cr (Chromium)

Explanation :

The reactivity series of metal are arranged of the reactivity from the highest to the lowest. Reactivity series is used to determine the products of the single displacement reactions. In the single displacement reaction, the most reactive metal displaces the least reactive metal.

From the given reactivity series we conclude that there are two metal (Mg and Cr) are more reactive metal than the Ni and there are two metal (Pb and Cr) are less reactive metal than the Zn. So, the Cr (Chromium) is the metal which is more active than Ni and less active than Zn.

Hence, the correct option is, (2) Cr

7 0

4 years ago

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What is indicated by the methyl- prefix

Ugo [173]

Answer:

B

Explanation:

The methyl prefix means theres a CH3 group bonded to a carbon in a hydrocarbon. This is called branching because it looks like a branched tree. This is literally cheating but you do you.

3 0

2 years ago

Explain how tectonic plate movement could create another supercontinent like pangaea

Ksenya-84 [330]

The plates are moving and are for billions of years... they collide and that they rip apart. The plates carry the continents on their "backs"; if 2 plates -each with a continent- collide, then a supercontinent is created. The landmass of Asian nation accustomed be an isolated block concerning 30-50 million years ago; it 1st crashed into Asia to form the range of mountains. If the movement of the plates brought all the continents along once more, one continent would type. At the instant plate, movements aren't heading in this direction.

7 0

3 years ago

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