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
Rzqust [24]
4 years ago
7

The zinc within a copper-plated penny will dissolve in hydrochloric acid if the copper coating is filed down in several spots (s

o that the hydrochloric acid can get to the zinc). The reaction between the acid and the zinc is as follows: 2H+(aq)+Zn(s)→H2(g)+Zn2+(aq). When the zinc in a certain penny dissolves, the total volume of gas collected over water at 25 ∘C was 0.949 L at a total pressure of 758 mmHg .
Chemistry
1 answer:
Mrac [35]4 years ago
3 0

Answer:

Mass of hydrogen gas evolved is 0.0749 grams.

Explanation:

Total pressure of the gases = p = 758 mmHg

Vapor pressure of water = 23.78 mmHg

Pressure of hydrogen gas ,P =  p - 23.78 mmHg = 758 mmHg - 23.78 mmHg

P = 734.22 mmHg = \frac{734.22}{760} atm=0.966 atm

Temperature  of of hydrogen gas ,T= 25°C =298.15 K

Volume of hydrogen gas = V = 0.949 L

Moles of hydrogen gas =n

PV = nRT (Ideal gas equation )

n=\frac{PV}{RT}=\frac{0.966 atm\times 0.949 L}{0.0821 atm L/mol K\times 298.15 K}

n = 0.03745 mol

Moles of hydrogen gas = 0.03745 mol

Mass of  0.03745 moles of hydrogen gas  = 0.03745 mol × 2 g/mol = 0.0749 g

Mass of hydrogen gas evolved is 0.0749 grams.

You might be interested in
Calnexin and calreticulin catalyze the removal of the final glucose residue from glycoproteins during the folding process. True
zloy xaker [14]

Answer:

Explanation:

A) False.

Glucosidase (not calnexin nor calreticulin) helps to remove glucose residue.

Both calnexin and calreticulin rather have an affinity for last glucose residue of misfolded protein (Only misfolded proteins are marked by glycosyltransferase by attaching glucose residue). They attach with misfolded protein and with the help of other proteins like ERp57 (a type of protein disulfide isomerase) and try to fold it properly. If protein is properly folded then glucosidase removes the glucose residue thereby releasing the properly folded protein from calnexin or calreticulin. and now protein is transported to the Golgi body. If folding is still not proper then the same cycle of glycosylation -binding of calnexin/calreticulin and effort to fold it properly is repeated.

B) True.

Transketolase is a key enzyme of the pentose phosphate pathway. It contains thiamine diphosphate (TPP) as a cofactor. it does transfer 2 carbon residue from a ketose to aldose. So, effectively it converts one ketose sugar to aldose with 2 carbonless and aldose to ketose with 2 carbon more.

C) True.

Theoretically, for the evolution of one molecule of oxygen, only 8 photons are required. But in practice, it is known that there are many variants like wavelength and the energy of the photon. The larger the wavelength, like the one which is used in PS1 (more than 700nM), the lesser the energy. Secondly, the energy of the photon is also wasted as heat energy. Because of these factors, more than 8 photons are needed in reality.

D) Wrong.

Fructose 2,6 bisphosphate is a key substrate and affects both the enzymes- phosphofructokinase and fructose bisphosphatase allosterically during gluconeogenesis. It strongly favors the breakdown of glucose during glycolysis by activating phosphofructokinase but it inhibits fructose bisphosphatase. Hence it activates the kinase enzyme while inhibiting the phosphatase and maintains a huge supply of glucose in the system.

E) Wrong.

The Calvin cycle shares similarity with the pentose phosphate pathway as both are involved in the synthesis of sugar (Triose and Ribose). However, it does not share similarity with enzymes of glycolysis (which is primarily focused on the breakdown of glucose) and gluconeogenesis.

8 0
3 years ago
Which type of atom has the strongest attraction for electrons in bond formation? barium (Ba) chlorine (Cl) iodine (I) strontium
bezimeni [28]

Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.
The type of atom has the strongest attraction for electrons in bond formation Chlorine (Ci) c<span>onsider the location of barium, chlorine, iodine, and strontium on the periodic table.</span>
6 0
3 years ago
Read 2 more answers
An unknown element sample has 2 isotopes present. The first isotope has a mass of 6.017 amu and is
oksano4ka [1.4K]

Answer:

Calculating Atomic Mass

Change each percent abundance into decimal form by dividing by 100. Multiply this value by the atomic mass of that isotope. Add together for each isotope to get the average atomic mass.

Explanation:

have a nice day

8 0
2 years ago
Calcule la molaridad de una solución acuosa de ácido sulfúrico (H₂SO₄) que se preparó al mezclar, en un recipiente aforado, 4 mo
oee [108]

Considerando la definición de molaridad, la molaridad de una solución acuosa de ácido sulfúrico (H₂SO₄) es 0.5 \frac{moles}{litro}.

La molaridad es una medida de la concentración de un soluto en una disolución que se define como el número de moles de soluto que están disueltos en un determinado volumen.

La molaridad de una solución se calcula dividiendo los moles del soluto por el volumen de la solución:

Molaridad=\frac{numero de moles de soluto}{volumen}

La Molaridad se expresa en las unidades \frac{moles}{litro}.

En este caso, sabes que una solución acuosa se preparó al mezclar 4 moles del ácido con suficiente agua hasta completar 8 litros de solución. Entonces, sabes que:

  • número de moles de soluto= 4 moles
  • volumen= 8 litros

Reemplazando en la definición de molaridad:

Molaridad=\frac{4 moles}{8 litros}

Resolviendo:

Molaridad= 0.5 \frac{moles}{litro}

Finalmente, la molaridad de una solución acuosa de ácido sulfúrico (H₂SO₄) es 0.5 \frac{moles}{litro}.

<em>Aprende más</em>:

  • brainly.com/question/17647411?referrer=searchResults
  • brainly.com/question/21276846?referrer=searchResults

8 0
3 years ago
How many moles are there in 87.2 g of zinc fluoride?
Sladkaya [172]

Answer:

what I got was 0.8435160945347224 moles

7 0
3 years ago
Other questions:
  • On a clear day at sea level, with a temperature of 25 °C, the partial pressure of N2 in air is 0.78 atm and the concentration of
    14·1 answer
  • What precipitate, if any, forms when aqueous solutions of li2so4 and nai are mixed?
    6·1 answer
  • a solution has a volume of 2.0L and contains 36.0 g of glucose. If the molar mass of glucose is 180 g/mol, what is the morality
    11·1 answer
  • What subatomic particle has negligible mass and travels around outside the nucleus?
    12·1 answer
  • To what volume (in milliliters) should you dilute 100.0 mL of a 5.50 M solution of CaCl2 solution to obtain a 0.950 M solution o
    8·1 answer
  • What precipitate sometimes forms during an acid-base neutralization reaction?
    7·2 answers
  • Find the number of formula units in 30 moles of h3po4
    11·1 answer
  • Nuclear energy is produced when scientists force uranium (U) atoms to break apart. With this in mind, examine the list below. If
    13·2 answers
  • En relación a la escala de ph se puede decir lo siguiente: I. Mientras más cerca del 8 la sustancia es más básica II. El papel t
    14·1 answer
  • 4) What type of weather events cause weathering and erosion?
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!