Elements in the same group have ____

3.5g of a Certain compound X, known to be made of carbon, hydrogen, and perhaps oxygen, and to have a molecular molar mass of 15

shutvik [7]

Answer:

C₅H₁₀O₅

Explanation:

1. Calculate the mass of each element in 2.78 mg of X.

(a) Mass of C

$\text{Mass of C} = \text{5.13 g CO}_{2}\times \dfrac{\text{12.01 g C}}{\text{44.01 g }\text{CO}_{2}}= \text{1.400 g C}$

(b) Mass of H

$\text{Mass of H} = \text{2.10 g H$_{2}$O}\times \dfrac{\text{2.016 g H}}{\text{18.02 g H$_{2}$O}} = \text{0.2349 g H}$

(c) Mass of O

Mass of O = 3.5 - 1.400 - 0.2349 = 1.87 g

2. Calculate the moles of each element

$\text{Moles of C = 1400 mg C}\times\dfrac{\text{1 mmol C}}{\text{12.01 mg C }} = \text{116.6 mmol C}\\\\\text{Moles of H = 234.9 mg H} \times \dfrac{\text{1 mmol H}}{\text{1.008 mg H}} = \text{233.1 mmol H}\\\\\text{Moles of O = 1870 mg O} \times \dfrac{\text{1 mmol O}}{\text{16.00 mg O}} = \text{116 mmol O}$

3. Calculate the molar ratios

Divide all moles by the smallest number of moles.

$\text{C: } \dfrac{116.6}{116.6}= 1\\\\\text{H: } \dfrac{233.1}{116.6} = 1.999\\\\\text{O: } \dfrac{116}{116.6} = 1.00$

4. Round the ratios to the nearest integer

C:H:O = 1:2:1

5. Write the empirical formula

The empirical formula is CH₂O.

6. Calculate the molecular formula.

EF Mass = (12.01 + 2.016 + 16.00) u = 30.03 u

The molecular formula is an integral multiple of the empirical formula.

MF = (EF)ₙ

$n = \dfrac{\text{MF Mass}}{\text{EF Mass }} = \dfrac{\text{150 u}}{\text{30.03 u}} = 5.00 \approx 5$

MF = (CH₂O)₅ = C₅H₁₀O₅

The molecular formula of X is C₅H₁₀O₅.

8 0

3 years ago

The nucleus of an atom ok K-42 contains

horsena [70]

Number of proton K=19

so, 42 - 19 =23

then the answer in 19 protons and 23 neutrons

3 0

3 years ago

How many milliliters of water at 25.0°C with a density of 0.997 g/mL must be mixed with 163 mL of coffee at 97.9°C so that the r

Stolb23 [73]

Answer:

248 mL

Explanation:

According to the law of conservation of energy, the sum of the heat absorbed by water (Qw) and the heat released by the coffee (Qc) is zero.

Qw + Qc = 0

Qw = -Qc [1]

We can calculate each heat using the following expression.

Q = c × m × ΔT

where,

c: specific heat

m: mass

ΔT: change in the temperature

163 mL of coffee with a density of 0.997 g/mL have a mass of:

163 mL × 0.997 g/mL = 163 g

From [1]

Qw = -Qc

cw × mw × ΔTw = -cc × mc × ΔTc

mw × ΔTw = -mc × ΔTc

mw × (54.0°C-25.0°C) = -163 g × (54.0°C-97.9°C)

mw × 29.0°C = 163 g × 43.9°C

mw = 247 g

The volume corresponding to 247 g of water is:

247 g × (1 mL/0.997 g) = 248 mL

8 0

3 years ago

1. Write the balanced equation for the breakdown of hydrogen peroxide. The equation has been written, you just have to balance.

o-na [289]

The balanced equation is attached in the image below. The coefficients are 2, 2, blank.

7 0

3 years ago

Read 2 more answers

I need help on 3 and 4 please I'm very confused and can not answer these questions I'm in sixth grade and it's hard

OverLord2011 [107]

D. Wind will always move from areas of high pressure to low pressure. It's the reason we have weather, or one of them. Temperature is another factor.

B. That is the definition of the greenhouse effect.

4 0

3 years ago

Elements in the same group have _____.