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mamaluj [8]
3 years ago
13

How many electrons does calcium hace?

Chemistry
1 answer:
Alja [10]3 years ago
4 0
The number of electrons is 20. hope this helps
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If 200. g of water at 20°C absorbs 41 840 J of energy, what will its final temperature be? (Specific Heat of water is 4.184 J/g*
Elena-2011 [213]

Answer: The final temperature will be 70^0C

Explanation:

To calculate the specific heat of substance during the reaction.

q=m\times c\times (T_{final}-T_{initial})

where,

q = heat absorbed =41840 J

c = specific heat = 4.184J/g^0C

m = mass of water  = 200 g

T_{final} = final temperature =?

T_{initial}= initial temperature = 20^0C

Now put all the given values in the above formula, we get:

41840J=200g\times 4.184J/g^0C\times (T_{final}-20)^0C

T_{final}=70^0C

Thus the final temperature will be 70^0C

3 0
3 years ago
When HClO2 is dissolved in water, it partially dissociates according to the equation
Natasha_Volkova [10]

Answer:

x = 100 * 1.1897 = 118.97 %, which is > 100 meaning that all of the HClO2 dissociates

Explanation:

Recall that , depression present in freezing point is calculated with the formulae = solute particles Molarity x KF

0.3473 = m * 1.86

Solving, m = 0.187 m

Moles of HClO2 = mass / molar mass = 5.85 / 68.5 = 0.0854 mol

Molality = moles / mass of water in kg = 0.0854 / 1 = 0.0854 m

Initial molality

Assuming that a % x of the solute dissociates, we have the ICE table:

                 HClO2         H+    +   ClO2-

initial concentration:       0.0854                    0             0

final concentration:      0.0854(1-x/100)   0.0854x/100   0.0854x / 100

We see that sum of molality of equilibrium mixture = freezing point molality

0.0854( 1 - x/100 + x/100 + x/100) = 0.187

2.1897 = 1 + x / 100

x = 100 * 1.1897 = 118.97 %, which is > 100 meaning that all of the HClO2 dissociates

3 0
3 years ago
Calculate the χacetone and χcyclohexane in the vapor above the solution. p°acetone = 229.5 torr and p°cyclohexane = 97.6 torr.
Ulleksa [173]
First calculate the mole fraction of each substance:
Acetone: 2.88 mol ÷ (2.88 mol + 1.45 mol) = 0.665
Cyclohexane: 1.45 ÷ (2.88 mol + 1.45 mol) = 0.335
Raoult's Law: P(total) = P(acetone) · χ(acetone)  + P(cyclohexane) · χ(cyclohexane).
P(total) = 229.5 torr · 0.665 + 97.6 torr · 0.335
P(total) = 185.3 torr
χ for acetone: 229.5 torr · 0.665 ÷ 185.3 torr = 0.823 
χ for cyclohexane:  97.6 torr · 0.335 ÷ 185.3 torr = 0.177
7 0
3 years ago
Read 2 more answers
The Goodyear blimp contains 5.7 x 10^6 L of helium at 25 degrees Celsius and 1 atm. What is the mass in grams of the helium insi
anygoal [31]

Answer:

1.72x10⁻⁵ g

Explanation:

To solve this problem we use the PV=nRT equation, where:

  • P = 1 atm
  • V = 5.7x10⁶ L
  • n = ?
  • R = 0.082 atm·L·mol⁻¹·K⁻¹
  • T = 25 °C ⇒ (25+273.16) = 298.16 K

And we <u>solve for n</u>:

  • 1 atm * 5.7x10⁶ L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 298.16 K
  • n = 4.29x10⁻⁶ mol

Finally we <u>convert moles of helium to grams</u>, using its <em>molar mass</em>:

  • 4.29x10⁻⁶ mol * 4 g/mol = 1.72x10⁻⁵ g

8 0
3 years ago
Blackmail threat of informational disclosure is an example of which threat category?
Rashid [163]

Answer:

Information Extortion.

Explanation:

Computer oriented crime also known as cyber crime that intentionally harm the victims. The complete data of the company or net banking information can be hacked easily by the cyber crime.

Different category of the threats are included in the cyber crime. The information extortion threat is the crime in which the hackers hack complete information and control the data of the victim. The criminal an black mail the victim regarding the hacked data.

Thus, the correct answer is information extortion.

6 0
3 years ago
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