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3 years ago

Arrange the following elements in order of decreasing electronegativity:

Chemistry

1 answer:

faltersainse [42]3 years ago

3 0

Answer:

Be,Mg,Ca,Sr,Ba.Ra[down the group electronegativity is decreasing]

Explanation:

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Choose the number of significant figures indicated 0.06

Alex17521 [72]

Answer:

Explanation:

8 0

3 years ago

The empirical formula of a compound is CH. At 200 degree C, 0.145 g of this compound occupies 97.2 mL at a pressure of 0.74 atm.

Vladimir [108]

Answer:

The molecular formula = $C_{6}H_{6}$

Explanation:

Given that:

Mass of compound, m = 0.145 g

Temperature = 200 °C

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15

So,

T = (200 + 273.15) K = 473.15 K

V = 97.2 mL = 0.0972 L

Pressure = 0.74 atm

Considering,

$n=\frac{m}{M}$

Using ideal gas equation as:

$PV=\frac{m}{M}RT$

where,

P is the pressure

V is the volume

m is the mass of the gas

M is the molar mass of the gas

T is the temperature

R is Gas constant having value = 0.0821 L.atm/K.mol

Applying the values in the above equation as:-

$0.74\times 0.0972=\frac{0.145}{M}\times 0.0821\times 473.15$

$M=78.31\ g/mol$

The empirical formula is = $CH$

Molecular formulas is the actual number of atoms of each element in the compound while empirical formulas is the simplest or reduced ratio of the elements in the compound.

Thus,

Molecular mass = n × Empirical mass

Where, n is any positive number from 1, 2, 3...

Mass from the Empirical formula = 12 + 1 = 13 g/mol

Molar mass = 78.31 g/mol

So,

Molecular mass = n × Empirical mass

78.31 = n × 13

⇒ n ≅ 6

The molecular formula = $C_{6}H_{6}$

6 0

3 years ago

24. Element X has five valence electrons, element Y has one valence electron, and element Z has one valence electron. Which two

natka813 [3]

Elements Y and elements Z would have similar properties due to the fact that they both posses the same number of valence electrons. They both have a single valence electron that determines the corresponding elements bonding properties and the fact that it can either donate 1 valence electron to produce an ion that would be attracted to another atom, that is also an ion. Assuming that these elements are group 1 elements, they do not undergo in covalent bonding.

3 0

3 years ago

Read 2 more answers

How many molecules are in 3 moles of NaCl?

PtichkaEL [24]

Answer:

Given : No. Of moles = 1.5

To calculate : no. Of molecules =N

We know that moles = N / 6.022 x 10²³

Therefore, 1.5 x 6.022 x 10²³ = N

Hence N = 9.0330x 10²³ molecules

3 0

3 years ago

Determine the percent water in MgSO4*7H20?

Semmy [17]

Answer:

$\% H_2O=51.2\%$

Explanation:

Hello!

In this case, since the percent water is computed by dividing the amount of water by the total mass of the hydrate; we infer we first need the molar mass of water and that of the hydrate as shown below:

$MM_{MgSO_4* 7H_2O}=120.36 g/mol+7*18.02g/mol\\\\MM_{MgSO_4* 7H_2O}=246.5g/mol$

Thus, the percent water is:

$\% H_2O=\frac{7*MM_{H_2O}}{MM_{MgSO_4* 7H_2O}} *100\%\\\\$

So we plug in to obtain:

$\% H_2O=\frac{7*18.02}{246.5} *100\%\\\\\% H_2O=51.2\%$

Best regards!

5 0

3 years ago