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3 years ago

The number of periods/series in Mendeleev's Periodic table isA. 10B. 13C. 12D. 14

Chemistry

1 answer:

butalik [34]3 years ago

5 0

Answer: The number of series in Mendeleev's Periodic table is 12.

Explanation:

Horizontal rows present in the periodic table are called periods. Vertical rows in the periodic table are called series.

Mendeleev gave periodic table in the year 1869 by arranging elements according to their atomic weights a in tabular form.

Mendeleev's periodic table depicts 12 periods/series.

Thus, we can conclude that the number of periods/series in Mendeleev's Periodic table is 12.

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John rode 3150 m at an average speed of 350 m/min.If he had ridden at average of 375 m/min instead. How much sooner would it hav

Svet_ta [14]

Explanation:

Given that:

Distance traveled = 3150m

Average speed = 350m/min

Suggested speed = 375m/min

Unknown:

Time = ?

Solution:

Speed is the rate of change of distance with time.

it is mathematically expressed as;

speed = $\frac{distance }{time}$

Initial time using speed 350m/min can be calculated by making time the subject of the formula;

time taken = $\frac{distance }{speed}$

time taken at speed of speed of 350m/min = $\frac{3150}{350}$ = 9min

to seconds = 9 x 60 = 540 seconds

time taken at speed of 375m/min = $\frac{3150}{375}$ = 8.4min

to seconds = 8.4 x 60 = 504 seconds.

It could have taken 504 seconds sooner saving 36 seconds.

learn more:

Speed brainly.com/question/10177389

#learnwithBrainly

7 0

3 years ago

1) The heat of combustion for the gases hydrogen, methane and ethane are −285.8, −890.4 and −1559.9 kJ/mol respectively at 298K.

Morgarella [4.7K]

Answer:

The enthalpy of the reaction is 64.9 kJ/mol.

Explanation:

$H_2 + \frac{1}{2}O_2\rightarrow H_2O,\Delta H_1 =-285.8 kJ$ ..[1]

$CH_4 + 2O_2\rightarrow CO_2 + 2H_2O,\Delta H_2 =-890.4 kJ$ ..[2]

$C_2H_6 + \frac{7}{2}O_2\rightarrow 2CO_2 + 3H_2O,\Delta H_3= -1559.9 kJ$ ..[3]

$2CH_4(g)\rightarrow C_2H_6(g) + H_2(g),\Delta H_4=?$ ..[4]

2 × [2] - [1]- [3] = [4] (Using Hess's law)

$\Delta H_4=2\times \Delta H_2 -\Delta H_1 -\Delta H_3$

$\Delta H_4=2\times (-890.4 kJ)-(-285.8 kJ) -(-1559.9 kJ)$

$\Delta H_4=64.9 kJ/mol$

The enthalpy of the reaction is 64.9 kJ/mol.

3 0

3 years ago

Density of 30.00 mL of H2O

ohaa [14]

its not possible sorry

6 0

3 years ago

If 294 grams of FeS2 is allowed ti react with 176 grams of O2 according to the following equation how many grams of Fe2O3 are pr

podryga [215]

You must balance your equation correctly.
Here is your answer:

294gFeS2 x 1molFeS2/119.99 x 11mols O2/4mols FeS2--> 6.738mol O2

176gO2 x 1mol O2/32gO2 x 4mols FeS2/11mol FeS2--> 2mols FeS2
Now choose the molecule with the lowest amount (Limiting Reagent)

2molsFeS2 x 2molsFe2O3/4molsFeS2 x 159.7g
159.7g Fe2O3 grams produced.

6 0

3 years ago

Read 2 more answers

A hot air balloon is filled with 15 moles helium gas and 5 moles nitrogen gas. What is the volume of the balloon at 1.01 atm and

kvasek [131]

Given:

Moles of He = 15

Moles of N2 = 5

Pressure (P) = 1.01 atm

Temperature (T) = 300 K

To determine:

The volume (V) of the balloon

Explanation:

From the ideal gas law:

PV = nRT

where P = pressure of the gas

V = volume

n = number of moles of the gas

T = temperature

R = gas constant = 0.0821 L-atm/mol-K

In this case we have:-

n(total) = 15 + 5 = 20 moles

P = 1.01 atm and T = 300K

V = nRT/P = 20 moles * 0.0821 L-atm/mol-K * 300 K/1.01 atm = 487.7 L

Ans: Volume of the balloon is around 488 L

3 0

3 years ago

The number of periods/series in Mendeleev's Periodic table isA. 10B. 13C. 12D. 14​

The number of periods/series in Mendeleev's Periodic table isA. 10B. 13C. 12D. 14