answer.
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
Nina [5.8K]
2 years ago
14

Up to a point, the elongation of a spring is directly proportional to the force applied to it. Once you extend the spring more t

han 10.0 centimeters, however, it no longer follows that simple linear rule. What force will result in stretching the spring 10.0 centimeters?
A.1.2 newton
B.2.2 newton
C2.5 newton
D.3.5 newton
Chemistry
1 answer:
lana [24]2 years ago
8 0

yes 2.5 is correct for plato!

You might be interested in
Write a net ionic equation for the reaction that occurs when nickel(ii carbonate and excess hydrobromic acid (aq are combined.
seropon [69]
First, we write the reaction equation:
NiCO₃ + 2HBr → NiBr₂ + H₂CO₃

Now, writing this in ionic form:
NiCO₃ + 2H⁺ + 2Br⁻ → NiBr₂ + 2H⁺ + CO₃⁻²

(NiCO₃ is insoluble so it does not dissociate in to ions very readily)

Overall equation:
NiCO₃ + 2Br⁻ → NiBr₂ + CO₃⁻²
7 0
2 years ago
In the reaction C + O2 → CO2, 18 g of carbon react with oxygen to produce 72 g of carbon dioxide. What mass of oxygen would be n
bulgar [2K]
<span>Molar mass(C)= 12.0 g/mol
Molar mass (O2)=2*16.0=32.0 g/mol
Molar mass (CO2)=44.0 g/mol

18g C*1mol C/12 g C = 1.5 mol C

                                 C +     O2 →                CO2

from reaction       1 mol    1 mol              1 mol
from problem     1.5 mol   1.5 mol         1.5 mol

1.5 mol O2*32 g O2/1 mol O2 = 48 g O2

In reality this reaction requires only 48 g O2 for 18 g carbon.
And from 18 g carbon you can get only
1.5 mol CO2*44 g CO2/1 mol CO2=66 g CO2
But these problem has 72g CO2. The best that we can think, it is a mix of CO2 and O2.
So to find all amount  of O2  that was added for the reaction (probably people who wrote this problem wanted this)
we need  (the mix of 72g - mass of carbon 18 g)= 54 g.
So the only answer that is possible is 
</span><span>2.) 54 g.</span>
3 0
2 years ago
Small beads of iridium-192 are sealed in a plastic tube and inserted through a needle into breast tumors. If an Ir-192 sample ha
Stells [14]

Answer:

296.1 day.

Explanation:

  • The decay of radioactive elements obeys first-order kinetics.
  • For a first-order reaction: k = ln2/(t1/2) = 0.693/(t1/2).

Where, k is the rate constant of the reaction.

t1/2 is the half-life time of the reaction (t1/2 = 1620 years).

∴ k = ln2/(t1/2) = 0.693/(74.0 days) = 9.365 x 10⁻³ day⁻¹.

  • For first-order reaction: <em>kt = lna/(a-x).</em>

where, k is the rate constant of the reaction (k = 9.365 x 10⁻³ day⁻¹).

t is the time of the reaction (t = ??? day).

a is the initial concentration of Ir-192 (a = 560.0 dpm).

(a-x) is the remaining concentration of Ir-192 (a -x = 35.0 dpm).

<em>∴ kt = lna/(a-x)</em>

(9.365 x 10⁻³ day⁻¹)(t) = ln(560.0 dpm)/(35.0 dpm).

(9.365 x 10⁻³ day⁻¹)(t) = 2.773.

<em>∴ t </em>= (2.773)/(9.365 x 10⁻³ day⁻¹) =<em> 296.1 day.</em>

5 0
2 years ago
Assuming ideal behavior, how many moles of argon would you need to fill a 14.0×12.0×10.0 ft room? assume atmospheric pressure of
Blababa [14]

We use the formula:

PV = nRT

First let us get the volume V:

volume = 14 ft * 12 ft * 10 ft = 1,680 ft^3

Convert this to m^3:

volume = 1680 ft^3 * (1 m / 3.28 ft)^3 = 47.61 m^3

 

n = PV / RT

n = (1 atm) (47.61 m^3) / (293.15 K * 8.21x10^-5 m3 atm / mol K)

<span>n = 1,978.13 mol</span>

4 0
2 years ago
Coal gasification is a multistep process to convert coal into cleaner-burning fuels. In one step, a coal sample reacts with supe
ddd [48]

Answer :

The enthalpy of reaction is, -187.6 kJ/mol

The total heat will be, -2251 kJ

Explanation :

According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.

According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.

(a) The formation of CH_4 will be,

2C(coal)+2H_2O(g)\rightarrow CH_4(g)+CO_2(g)    \Delta H_{rxn}=?

The intermediate balanced chemical reaction will be,

(1) C(coal)+H_2O(g)\rightarrow CO(g)+H_2(g)     \Delta H_1=29.7kJ

(2) CO(g)+H_2O(g)\rightarrow CO_2(g)+H_2(g)    \Delta H_2=-41kJ

(3) CO(g)+3H_2(g)\rightarrow CH_4(g)+H_2O(g)    \Delta H_3=-206kJ

We are multiplying equation 1 by 2 and then adding all the equations, we get :

(b) The expression for enthalpy of reaction will be,

\Delta H_{rxn}=2\times \Delta H_1+\Delta H_2+\Delta H_3

\Delta H_{rxn}=(2\times 29.7)+(-41)+(-206)

\Delta H_{rxn}=-187.6kJ/mol

Therefore, the enthalpy of reaction is, -187.6 kJ/mol

(c) Now we have to calculate the total heat.

\Delta H=\frac{q}{n}

or,

q=\Delta H\times n

where,

\Delta H = enthalpy change = -187.6 kJ/mol

q = heat = ?

n = number of moles of coal = \frac{1.00\times 1000g}{12.00g/mol}=83.33mol

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

q=(-187.6kJ/mol)\times (83.33mol)=-2.251kJ

Thus, the total heat will be, -2251 kJ

4 0
2 years ago
Other questions:
  • The specific heat of water is 4.18 J/g•°C. How much heat does 225.0 g of water release when it cools from 85.5°C to 50.0°C? Ente
    11·2 answers
  • What is the net ionic equation of the reaction of BeCl2 with NaOH
    6·1 answer
  • If a gas at 25.0 °C occupies 3.60 liters at a pressure of 1.00 atm, what will be its volume at a pressure of 2.50 atm?
    12·2 answers
  • How many mL of a 4.50M NaBr solution are needed to make 250 mL of a 0.75M solution of NaBr?
    10·1 answer
  • A student pours exactly 26.9 mL of HCl acid of unknown molarity into a beaker. The student then adds 2 drops of the indicator an
    13·1 answer
  • a compound is found to have 46.67% nitrogen, 6.70% hydrogen, 19.98% carbon and 26.65% oxygen, what is the empirical formula?
    15·1 answer
  • The composition of dry air at sea level is 78.03% N2, 20.99% O2, and 0.033% CO2 by volume. (a) calculate the average molar mass
    12·1 answer
  • ) A concentration cell is based on the aqueous reaction
    6·1 answer
  • 18) Why are the large oak trees so important for storks? Where are<br> they found?<br> 1
    8·1 answer
  • A solution was made in a 200.00 mL volumetric flask consisting of 18.00 mL of 2.125 M HCl and 0.4104 grams of CaCO3, followed by
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!