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2 years ago

Please show work: Question below

Chemistry

1 answer:

ozzi2 years ago

3 0

Answer:

b) 2.0 mol

Explanation:

Given data:

Number of moles of Ca needed = ?

Number of moles of water present = 4.0 mol

Solution:

Chemical equation:

Ca + 2H₂O → Ca(OH)₂ + H₂

now we will compare the moles of Ca and H₂O .

H₂O : Ca

2 : 1

4.0 : 1/2×4.0 = 2.0 mol

Thus, 2 moles of Ca are needed.

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SOVA2 [1]

Answer:

The minimum concentration of acetaminophen that can be detected by new= 10μg/mL

Volume of blood sample=2ml

Minimum mass of acetaminophen that can be detected by automated system= 10×2= 20μg= 0.020mg

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2 years ago

At 25°C, the equilibrium constant Kc for the reaction in thesolvent CCl4 2BrCl <----> Br2 + Cl2 is 0.141. If the initial c

ivolga24 [154]

Answer: The equilibrium concentration of bromine gas is 0.00135 M

Explanation:

We are given:

Initial concentration of chlorine gas = 0.0300 M

Initial concentration of bromine monochlorine = 0.0200 M

For the given chemical equation:

$2BrCl\rightleftharpoons Br_2+Cl_2$

Initial: 0.02 0.03

At eqllm: 0.02-2x x 0.03+x

The expression of $K_c$ for above equation follows:

$K_c=\frac{[Br_2]\times [Cl_2]}{[BrCl]^2}$

We are given:

$K_c=0.141$

Putting values in above equation, we get:

$0.141=\frac{x\times (0.03+x)}{(0.02-2x)^2}\\\\x=-0.96,+0.00135$

Neglecting the value of x = -0.96 because, concentration cannot be negative

So, equilibrium concentration of bromine gas = x = 0.00135 M

Hence, the equilibrium concentration of bromine gas is 0.00135 M

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3 years ago

When sulfur burns, it forms sulfur dioxide (SO2). Its chemical reaction is S + O2 → SO2.

Elenna [48]

Answer:

The mass of SO2 will be equal to the sum of the mass of S and O2.

Explanation:

This can be explained by the Law of Conservation of Mass. This law states that mass can neither be created nor destroyed. Knowing this, we can say that the reactants of a chemical reaction must be equal to the products.

In this case, the reactants Sulfur (S) and Oxygen (O2) must equal the mass of the product Sulfur Dioxide (SO2). Therefore, the statement "The mass of SO2 will be equal to the sum of the mass of S and O2" is correct.

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2 years ago

I need an answer now please asap and you will me marked brainiest please it's missing I need it now.

valentina_108 [34]

Answer:

C. NaHCO3 → Na2CO3 + H2O + CO2

Explanation:

» For a balanced equation, the number of atoms of reactants and products must be equal.

» In equation C, the reactant side has one sodium atom while ptoduct side has 2 sodium atoms.

» The balanced equations mus be;

${ \rm{ 2NaHCO _{3(aq)} → Na _{2}CO _{3(s)}+ H _{2} O _{(l)} + }CO _{2(g)} }$