1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Airida [17]
3 years ago
13

The specific heat of ethanol is 2.44 J/g ֯C. How many kJ of energy are required to heat 50.0 grams of ethanol from -20 ֯C to 68

֯C? (heat equation)
Chemistry
1 answer:
Aliun [14]3 years ago
5 0

Answer:

Heat energy required (Q) = 10.736 KJ

Explanation:

Given:

Specific heat of ethanol (C) = 2.44 J/g °C

Mass of ethanol (M) = 50 gram

Initial temperature (T1) = -20°C

Final temperature (T1) = 68°C

Find:

Heat energy required (Q) = ?

Computation:

Change in temperature (ΔT) = 68°C - (-20°C)

Change in temperature (ΔT) = 88°C

Heat energy required (Q) = mC(ΔT)

Heat energy required (Q) = (50)(2.44)(88)

Heat energy required (Q) = 10,736 J

Heat energy required (Q) = 10.736 KJ

You might be interested in
An unknown radioactive substance has a half-life of 3.20hours . If 46.2g of the substance is currently present, what mass A0 was
iogann1982 [59]

Answer:

a) a0 was 46.2 grams

b) It will take 259 years

c) The fossil is 1845 years old

Explanation:

<em>An unknown radioactive substance has a half-life of 3.20hours . If 46.2g of the substance is currently present, what mass A0 was present 8.00 hours ago?</em>

A = A0 * (1/2)^(t/h)

⇒ with A = the final amount = 46.2 grams

⇒ A0 = the original amount

⇒ t = time = 8 hours

⇒ h = half-life time = 3.2 hours

46.2 = Ao*(1/2)^(8/3.2)

Ao = 261.35 grams

<em>Americium-241 is used in some smoke detectors. It is an alpha emitter with a half-life of 432 years. How long will it take in years for 34.0% of an Am-241 sample to decay?</em>  

t = (ln(0.66))-0.693) * 432 = 259 years

It will take 259 years

<em>A fossil was analyzed and determined to have a carbon-14 level that is 80% that of living organisms. The half-life of C-14 is 5730 years. How old is the fossil?</em>

<em />

t = (ln(0.80))-0.693) * 5730 = 1845

The fossil is 1845 years old

7 0
3 years ago
This is the last free pts for the day but you have to answer this still to earn Brainliest, k? Guess what time zone I live in, d
BigorU [14]

Answer:

ummm Eastern time zone

8 0
3 years ago
Read 2 more answers
HELP ME I AM DUMB!!!!!!!!!!!!!!!!!!
densk [106]

Answer:

2H⁺(aq) + Sr(OH)₂(s) ⟶ Sr²⁺(aq) + 2H₂O(ℓ)

Explanation:

You aren't dumb. You just need more time to learn the concepts.

There are three steps you must follow. You must write the:

  1. Molecular equation
  2. Ionic equation
  3. Net ionic equation

1. Molecular equation

2HBr + Sr(OH)₂ ⟶ SrBr₂ + 2H₂O

To predict the states of the substances, we must remember some solubility rules:

  • HBr is a strong acid. It dissociates completely in water.
  • Most hydroxides are only slightly soluble. Unless the solution is quite dilute, I would write their states in water as "(s)", i.e., a suspension of the solid in water.
  • Salts containing Br⁻ are generally soluble.

Acids and bases react to give salts and water.

Thus, the molecular equation is

2HBr(aq) + Sr(OH)₂(s) ⟶ SrBr₂(aq) + 2H₂O(ℓ)

B. Ionic equation

You write all the soluble substances as ions.

2H⁺(aq)+ 2Br⁻(aq) + Sr(OH)₂(s) ⟶ Sr²⁺(aq) + 2Br⁻(aq) + 2H₂O(ℓ)

C. Net ionic equation

To get the net ionic equation, you cancel the ions that appear on each side of the ionic equation.

2H⁺(aq) + <u>2Br⁻(aq)</u> + Sr(OH)₂(s) ⟶ Sr²⁺(aq) + <u>2Br⁻(aq)</u> + 2H₂O(ℓ)

The net ionic equation is

2H⁺(aq) + Sr(OH)₂(s) ⟶ Sr²⁺(aq) + 2H₂O(ℓ)

3 0
2 years ago
The atomic weight of an atom is the sum of the mass of the particles in the nucleus of the atom. These particles are called?
Ludmilka [50]

Answer:

c) neutrons and protons

Explanation:

The nucleus of the atom contains only neutrons and protons. Electrons are not in the nucleus but outside the nucleus in 'atomic orbitals'.

5 0
2 years ago
Hclo is a weak acid (ka=4.0x10^-8) and so the salt naclo acts as a weak base. what is the ph of a solution that is 0.037 m in na
ankoles [38]

<u>Given:</u>

Concentration of NaClO = 0.037 M

ka (HClO) = 4.0*10⁻⁸

<u>To determine:</u>

The pH of the NaClO solution

<u>Explanation:</u>

The hydrolysis of the weak base can be represented by the ICE table shown below-

                ClO-      +     H2O    ↔    HClO    +       OH-

Initial        0.037M                              0                    0

Change         -x                                 +x                  +x

Equilibrium  (0.037-x)                        x                     x

kb  = kw/ka =  [HClO][OH-]/[ClO-]

10⁻¹⁴/4*10⁻⁸ = x²/(0.037-x)

x = [OH-] = 9.62*10⁻⁵

p[OH-] = -log[OH-] = -log [9.62*10⁻⁵] = 4.02

pH = 14-p[OH-] = 14 - 4.02 = 9.98

Ans: pH of the solution is 9.98


7 0
2 years ago
Other questions:
  • Acetone major species present when dissolved in water
    9·1 answer
  • Q # 6 which of the following equations has correct formulas and also is a balanced equation?
    15·1 answer
  • Determine the limiting reactant in a mixture containing 139 g of Se, 431 g of Cl2, and 110 g of H2O. Calculate the maximum mass
    10·1 answer
  • Acid &amp; Base Calculations Calculate the hydronium ion concentration for each. Tell whether it is an acid or a base. 1. pH = 5
    11·1 answer
  • calculate pressure exerted by 1.255 mol of CI2 in a volume of 5.005 L at a temperature 273.5 k using ideal gas equation
    8·1 answer
  • Send help thank u asap
    9·2 answers
  • in rutherford's gold foil experiment a very small number of alpha particles were deflected. what about the structure of the atom
    8·1 answer
  • Science, please help and thank you!!
    8·1 answer
  • ASAP will give brainliest!!!!
    10·1 answer
  • Magnesium and copper react with dilute acids to make salts and hydrogen gas<br> True<br> False
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!