239 Pu 4 He 94 2 Fill in the missing particle

For an alloy that consists of 91.0 g copper, 111 g zinc, and 7.51 g lead, what are the concentrations (a) of Cu (in at%), (b) of

viktelen [127]

Answer:

$\% Cu=45.2\%\\\\\% Zn=53.6\%\\\\\% Pb=1.2\%$

Explanation:

Hello!

In this case, given the masses of copper, zinc and lead, it is possible to compute the moles via their atomic masses first:

$n_{Cu}=\frac{91.0gCu}{63.55g/mol}=1.432mol\\\\ n_{Zn}=\frac{111gZn}{65.41g/mol}=1.697mol\\\\n_{Pb}=\frac{7.51gPb}{207.2g/mol}=0.0362mol\\$

Now, we compute the atomic percentages as shown below:

$\% Cu=\frac{1.432}{1.432+1.697+0.0362}*100\% =45.2\%\\\\\% Zn=\frac{1.697}{1.432+1.697+0.0362}*100\%=53.6\%\\\\\% Pb=\frac{0.0362}{1.432+1.697+0.0362}*100\%=1.2\%$

Best regards!

4 0

2 years ago

Which is a characteristic of a strong base

skelet666 [1.2K]

Acids or bases with weak bonds easily dissociate into ions and are called "strong" acids or bases. Table 1: Summary List of Characteristics for Strong and Weak Acids and Bases. All characteristics of acids and bases are related to whether the predominate forms are molecules and ions. Characteristic.

3 0

3 years ago

Number 72 I need help

Mashutka [201]

A. Cs - 55 electrons, 55 protons, 77 neutrons
B. Co - 27 electrons, 22 protons, 32 neutrons
C. Tm - 69 electrons, 69 protons, 94 neutrons
D. Zn - 30 electrons, 30 protons, 40 neutrons

For any neutral atom, protons = electrons = atomic number. Neutrons = atomic mass - atomic number.

7 0

3 years ago

Determine the heat of reaction for the process TiO2(s) + 4HCl(g) TiCl4(l) + 2H2(g) + O2(g) using the information given below: Ti

Aleks [24]

Answer : The heat of reaction for the process is, 1374.7 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.

The main chemical reaction is,

$TiO_2(s)+4HCl(g)\rightarrow TiCl_4(l)+2H_2(g)+O_2(g)$ $\Delta H_{rxn}=?$

The intermediate balanced chemical reaction will be,

(1) $Ti(s)+O_2(g)\rightarrow TiO_2(s)$ $\Delta H_1=-939.7kJ$

(2) $2HCl(g)\rightarrow H_2(g)+Cl_2(g)$ $\Delta H_2=-184.6kJ$

(3) $Ti(s)+2Cl_2(g)\rightarrow TiCl_4(l)$ $\Delta H_3=-804.2kJ$

We reversing reaction 1, 3 and multiplying reaction 2 by 2 and then adding all the equations, we get :

(1) $TiO_2(s)\rightarrow Ti(s)+O_2(g)$ $\Delta H_1=939.7kJ$

(2) $4HCl(g)\rightarrow 2H_2(g)+2Cl_2(g)$ $\Delta H_2=2\times (-184.6kJ)=-369.2kJ$

(3) $TiCl_4(l)\rightarrow Ti(s)+2Cl_2(g)$ $\Delta H_3=804.2kJ$

The expression for heat of reaction for the process is:

$\Delta H_{rxn}=\Delta H_1+\Delta H_2+\Delta H_3$

$\Delta H_{rxn}=(939.7kJ)+(-369.2kJ)+(804.2kJ)$

$\Delta H_{rxn}=1374.7kJ$

Therefore, the heat of reaction for the process is, 1374.7 kJ

3 0

3 years ago

Used to describe an atom’s ability to chemically bond with another atom

zepelin [54]

Answer:

"Electronegativity" is the atom's ability to chemically bond with another atom.

Explanation:

Electronegativity is the ability of the atom to attract the electrons towards another atom to it, these two atoms are associated through a bond. The phenomena is based on the atom's ionization energy and the electron affinity. The formation of the chemical bond takes place when the atoms share the electrons they have in outer shells. In other words we can say two atoms fuse together to form chemical bond.

7 0

3 years ago