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
wlad13 [49]
3 years ago
10

At STP, which 4.0-gram zinc sample will react fastest with dilute hydrochloric acid?

Chemistry
1 answer:
marusya05 [52]3 years ago
8 0
At STP, a powered 4.0-gram zinc sample would react fastest dilute hydrochloric acid. 
You might be interested in
As you go down a family or group on the periodic table *
pickupchik [31]

Answer:

The elements become less reactive.

Explanation:

As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction and reactivity increases because of greater electron affinity.

As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased. The electron affinity decreases because of shielding effect and thus atom become less reactive.

7 0
2 years ago
Plants that have nigrogen fixing bacteria in their roots are called​
iragen [17]

Plants that have nigrogen fixing bacteria in their roots are called​

legumes.

8 0
2 years ago
How many moles of water as a gas can be formed 2.45 L
Alex17521 [72]

Answer:

0.11mole

Explanation:

Let us assume that the condition is at standard temperature and pressure(STP);

 Given parameters:

        Volume of water  = 2.45L

   Unknown:

       Number of moles found in this volume of water  = ?

Solution;

 At STP;

                 Number of moles  = \frac{volume of gas}{22.4}

 Input the parameters and solve;

                  Number of moles of water  = \frac{2.45}{22.4}   = 0.11mole

The number of moles of water found is  0.11mole

4 0
3 years ago
5. What concentration of acid must be added to change the pH of 1 mM phosphate buffer from 7.4 to 7.3 (pKas of the phosphate buf
mr_godi [17]

Explanation:

According to the Henderson-Hasselbalch equation, the relation between pH and pK_{a} is as follows.

               pH = pK_{a} + log \frac{base}{acid}

where,     pH = 7.4 and pK_{a} = 7.21

As here, we can use the pK_{a} nearest to the desired pH.

So,      7.4 = 7.21 + log \frac{base}{acid}

             0.19 = log \frac{base}{acid}

            \frac{base}{acid} = 1.55

1 mM phosphate buffer means [HPO_{4}] + [H_{2}PO_{4}] = 1 mM

Therefore, the two equations will be as follows.

           \frac{HPO_{4}}{H_{2}PO_{4}} = 1.55 ............. (1)

  [HPO_{4}] + [H_{2}PO_{4}] = 1 mM ........... (2)        

Now, putting the value of [HPO_{4}] from equation (1) into equation (2) as follows.

             1.55[H_{2}PO_{4}] + [tex][H_{2}PO_{4}] = 1 mM

                        2.55 [H_{2}PO_{4}] = 1 mM

                             [H_{2}PO_{4}] = 0.392 mM

Putting the value of [H_{2}PO_{4}] in equation (1) we get the following.

                     0.392 mM + [HPO_{4}] = 1 mM

                          [HPO_{4}] = (1 - 0.392) mM

                              [HPO_{4}] = 0.608 mM

Thus, we can conclude that concentration of the acid must be 0.608 mM.

7 0
3 years ago
An exponent of "2" means that if we double the concentration of the reactant the rate doubles as well Exponents in rate laws are
Karo-lina-s [1.5K]

Answer:

- False.

- False.

- True.

- True.

Explanation:

Hello, for each statement we state:

- An exponent of "2" means that if we double the concentration of the reactant the rate doubles as well.

FALSE because considering a rate law like:

-r=kC^2

The exponent of "2" powers the concentration to the second power, not doubles the rate law, thus, if C is 3, for k=1, r will be -9. On the other hand if the rate is like:

-r=kC

The rate will be -3, that is why the rate is not doubled when the "2" in concentration is present.

- Exponents in rate laws are based on the coefficients from the balanced equation.

FALSE because for nonelemental chemical reactions, the exponents do not match with each species' stoichiometric coefficients in the rate law.

- The rate constant, k, takes into account the effect of activation energy and temperature on the reaction.

TRUE, since the Arrhenius equation allows us to prove the effect of the activation energy and the temperature:

k=Aexp(-\frac{Ea}{RT})

- Differential rate laws allow us to compare concentration and time.

TRUE as they are given like:

\frac{1}{\nu _A} \frac{dC_A}{dt} =\frac{1}{\nu _B} \frac{dC_B}{dt} =...

Best regards.

5 0
3 years ago
Other questions:
  • What is one way that cactus and camel are similar
    6·2 answers
  • Convert 3.82 inches to km
    8·2 answers
  • What is the volume of 8.50 moles of hydrogen gas?
    12·1 answer
  • The period 4 alkaline-earth metal has the name_______ . An isotope of this element having 20 neutrons has amass numberof _______
    15·1 answer
  • The dissolution of ammonium nitrate occurs spontaneously in water at 25°C. As NH4NO, dissolves, the temperature of the water dec
    6·1 answer
  • HELPPP PLZZ :/
    13·2 answers
  • Perform the following operation
    11·1 answer
  • Ca --> CaO --> CaCO3 --> CO2
    13·1 answer
  • Assume the following is a neutral atom.
    12·1 answer
  • Use the patterns you identified to estimate the likely melting point for potassium (K) in Group 1 and barium (Ba) in Group 2. En
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!