2. What will you change (the independent variable) in each test?

Read the given equation. 2Na + 2H2O ? 2NaOH + H2 During a laboratory experiment, a certain quantity of sodium metal reacted with

emmasim [6.3K]

Answer:

The number of moles of Na metal that used initially = 0.70 mol.

The quantity of Na metal used initially to produce 7.80 of H₂ gas = 16.02 g.

Explanation:

It is a stichiometry problem.

2Na + 2H₂O → 2NaOH + H₂,

The balanced equation shows that 2.0 moles of Na metal react with 2.0 moles of water to produce 2.0 moles of NaOH and 1.0 mole of H₂,

Firstly, we need to convert the volume of H₂ (7.80 L) produced to no. of moles (n) using the ideal gas law: PV = nRT,

where, P is the pressure of the gas in atm (P at STP = 1.0 atm),

V is the volume of the gas in L (V = 7.80 L),

n is the number of moles in mole,

R is the general gas constant (R = 0.082 L.atm/mol),

T is the temperature of the gas in K (T at STP = 0.0 °C + 273 = 273.0 K).

∴ The number of moles of H₂ gas (n) = PV / RT = [(1.0 atm)(7.80 L)] / [(0.082 L.atm/mol.K)(273.0 K)] = 0.35 mol.

Using cross multiplication:

2.0 moles of Na will produce → 1.0 mole of H₂, from the stichiometrey.

??? moles of Na will produce → 0.35 mole of H₂.

∴ The number of moles of Na metal that used initially = (2.0 mol)(0.35 mol) / (1.0 mol) = 0.70 mol.

Now, we can get the quantity of Na metal using the relation:

∴ mass = n x molar mass = (0.70 mol)(22.989 g/mol) = 16.02 g.

6 0

3 years ago

What is the function of a lyase enzyme?

elena55 [62]

Answer:

c. To facilitate a reaction of one substrate to form two products without the use of water

Explanation:

A lyase is an enzyme that catalyzes - accelerates the chemical reaction - in which a substrate is broken into two molecules. The reaction does not involve hydrolysis or oxidation, so the water molecule is not included in the chemical reaction. Thus, the enzyme facilitates the reaction in which a molecule (substrate) is decomposed into two molecules with the elimination of chemical bonds.

5 0

2 years ago

The ________________and ______________ of magma cause igneous rocks to form.

LekaFEV [45]

Answer:

The solidifying/cooling and crystallizing of magma causes igneous rocks to form.

6 0

2 years ago

Electron transfer is the term for this process. The resulting anion and cation are attracted by Coulombic forces and an ionic co

Nitella [24]

<h2>The compound formed is NaCl and $CaCl_{2}$ </h2>

Explanation:

PART 1:

Atomic number of sodium is 11.
Sodium(Na, Z = 11, Group 1A) will lose 1 electron to become $Na^{1+}$ which is isoelectronic to Neon (Ne ,Z = 10).
The symbol for the sodium ion is $Na^{+}$ .
Chlorine atom ( $Cl$ , Z = 17, Group 7A or 17) gains 1 elecron to be isoelectronic to neon.
The symbol for the compound formed is NaCl.
PART 2:
Atomic number of calcium is 20
Calcium(Ca, Z = 20 ,Group 2A) will lose two electrons to become $Ca^{2+}$ which is isoelectronic to argon.
The symbol for the ion is $Ca^{2+}.$
Two chlorine atoms (Cl, Z = 17, Group 7A or 17) each gains one electron to be isoelectronic to argon(Z = 18)
The symbol for the compound formed is $CaCl_{2}$ .