The following is NOT an example of a behavior:

How much current is drawn by a 40-W bulb in a 120-V circuit?

tia_tia [17]

Since power, P, equals iV, P/V = i, so at 120 V, a 40-watt bulb draws 1/3 A.

8 0

3 years ago

n unknown metal is either aluminum, iron or lead. If 150. g of this metal at 150.0 °C was placed in a calorimeter that contains

Nitella [24]

Answer : The metal used was iron (the specific heat capacity is $0.449J/g^oC$ ).

Explanation :

In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.

$q_1=-q_2$

$m_1\times c_1\times (T_f-T_1)=-m_2\times c_2\times (T_f-T_2)$

where,

$c_1$ = specific heat of unknown metal = ?

$c_2$ = specific heat of water = $4.184J/g^oC$

$m_1$ = mass of unknown metal = 150 g

$m_2$ = mass of water = 200 g

$T_f$ = final temperature of water = $34.3^oC$

$T_1$ = initial temperature of unknown metal = $150.0^oC$

$T_2$ = initial temperature of water = $25.0^oC$

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

$150g\times c_1\times (34.3-150.0)^oC=-200g\times 4.184J/g^oC\times (34.3-25.0)^oC$

$c_1=0.449J/g^oC$

Form the value of specific heat of unknown metal, we conclude that the metal used in this was iron (Fe).

Therefore, the metal used was iron (the specific heat capacity is $0.449J/g^oC$ ).

6 0

4 years ago

ure to answer all parts. The vapor pressure of ethanol (C2H5OH) at 20°C is 44 mmHg, and the vapor pressure of methanol (CH3OH) a

eimsori [14]

Answer:

$P_{met}=40.98mmHg\\\\P_{et}=24.82mmHg$

Explanation:

Hello

In this case, by considering the Raoult's law we can write:

$P_{met}=x_{met}P_{sat,met}\\\\P_{et}=x_{et}P_{sat,et}$

Whereas the purpose is to compute the pressures of both methanol and ethanol (pressures above the solution), thus, the first step is to compute the molar fractions:

$n_{met}=25.3gCH_3OH*\frac{1molCH_3OH}{32gCH_3OH}=0.791molCH_3OH\\ \\n_{et}=47.1gCH_3CH_2OH*\frac{1molCH_3CH_2OH}{46gCH_3CH_2OH}=1.02molCH_3CH_2OH\\\\x_{met}=\frac{0.791mol}{0.791mol+1.02mol}=0.436\\ \\x_{et}=1-x_{met}=1-0.436=0.564$

Therefore, the pressures turns out:

$P_{met}=0.436*94mmHg=40.98mmHg\\\\P_{et}=0.564*44mmHg=24.82mmHg$

Best regards.

8 0

3 years ago

As the volume of a 1 mole sample of gas increases, with the temperature remaining constant, the pressure exerted by the gas:

Vinvika [58]

I believe the correct answer would be decreases. At constant temperature, the volume and pressure are inversely related that is when one value increases the other decreases or as one decreases the other increases. Hope this helps. Have a nice day.

7 0

4 years ago

Is matter continuous and therefore has no finer structure or is it discontinuous and thus made or tiny particles

Marta_Voda [28]

Matter is discontinuous, and it is made of tiny particles called atoms

Explanation:

Matter is not a continuous structure, but it consists of tiny particles called atoms.

An atom consists of three types of particles:

Proton: the proton is in the nucleus of the atom. it has a positive electric charge of $+1.6\cdot 10^{-19}C$ (also called fundamental charge). Its mass is $1.67\cdot 10^{-27}kg$ .

Neutron: the neutron is also in the nucleus of the atom, but it has no electric charge. Its mass is similar to the mass of the proton (slightly heavier). Neutrons and protons are held together in the nucleus through the strong nuclear force.

Electron: electrons are found in a "cloud" outside the nucleus. Electron has negative electric charge equal to $-1.6\cdot 10^{-19}C$ . Its mass is much approximately 1800 times smaller than that of the proton, so it is considered as negligible.

Learn more about atoms and matter:

brainly.com/question/2757829

#LearnwithBrainly

7 0

3 years ago