Answer is: mass of <span>potassium bromide is 4.71 grams.
V(KBr) = 25.4 mL </span>÷ 1000 mL/L = 0.0254 L, volume of solution.
c(KBr) = 1.56 mol/L.
n(KBr) = c(KBr) · V(KBr).
n(KBr) = 1.56 mol/L 0.054 L.
n(KBr) = 0.0396 mol, amount of substance.
m(KBr) = n(KBr) · M(KBr).
m(KBr) = 0.0396 mol · 119 g/mol.
m(KBr) = 4.71 g.
M - molar mass.
Answer:
three valence electrons
Explanation:
Gallium has three electrons in the outer energy level and therefore has three valence electrons. The identification of valence electrons is vital because the chemical behavior of an element is determined primarily by the arrangement of the electrons in the valence shell.
Answer:
A beta particle
Explanation:
The radioactive particle must undergo a beta decay to have the mass number unchanged but the atomic number to have decreased by one.
This type of beta decay results in the emission of a positron which is a type of beta particle. It resembles an electron but it has a positive charge of 1.
Answer:
First write the balanced equation for the reaction of HCl with Zn (NOTE: the previous answer did NOT do this and thus obtained an incorrect answer)
Zn + 2HCl ==> ZnCl2 + H2(g)
moles of H2 desired: PV = nRT
n = PV/RT = (1 atm)(10L)/(0.0821 Latm/Kmol)(298K)
n = 0.409 mole H2 desired
moles Zn needed:
0.409 moles H2 x 1 mole Zn/2 moles HCl = 0.204 moles Zn needed
mass Zn needed = 0.204 moles Zn x 65.4 g/mol = 13.4 g Zn needed (to 3 sig. figs.)
Explanation:people always get this wrong but i got you
We are tasked to identify the term that characterize a pure sodium chloride in a jar. To solve for this, we need to us the classification of matter matrix which is
No
Uniform Properties-----> Heterogeneous Mixture
Yes|
| No
Fixed Composition?--------> Solution
Yes|
| No
Chemical Decomposable----> Element
Yes|
|
COmpound
Since the substance have a uniform properties and fixed compositions (pure) and can be chemically decompose through electrolysis, then it is a compound
